1

The challenge of L2 sandhi – vowel hiatus in Polish English1

Geoffrey Schwartz1, Grzegorz Aperliński

1, Anna Balas

1, Arkadiusz Rojczyk

2

1 Faculty of English – Adam Mickiewicz University in Poznań

2 Institute of English – University of Silesia, Katowice-Sosnowiec

Abstract

The production and perception of L2 vowel hiatus, like other sandhi phenomena, is a largely

unexplored area in the field of L2 phonology. This paper presents a production and perception

study of vowel hiatus in the speech of Polish learners of English. Polish and English appear to

show systematic differences in the realization of hiatus. Textbook descriptions of English

refer to ‘glide insertion’ and ‘linking/intrusive [r]’ as the preferred hiatus fillers in traditional

vernacular dialects. By contrast, in Polish hiatus is typically realized with glottal stops,

glottalization, or increases in spectral tilt. These differences suggest that vowel glottalization

may be a form of L1 interference in Polish English. The production results indicate that the

suppression of glottalization is an integral part of L2 phonological acquisition for advanced

Polish learners. The listening tests revealed that the realization of vowel hiatus (modal vs.

glottalized) has an effect on L1 English listeners’ ratings of foreign accentedness, but L2

learners’ ratings of comprehensibility are largely unaffected by the glottalization of hiatus.

Issues of phonological representation underlying the study and its hypotheses are also

discussed.

1 Introduction

Experimental research into second language (L2) phonology has focused to a large degree on

segmental features and contrasts. Two of the more popular areas of study have been vowel

contrasts (e.g. Escudero and Boersma, 2004) and the implementation of laryngeal features

(e.g. Flege and Eefting, 1987). In both areas the somewhat elusive notion of cross-language

phonetic similarity has played a significant role in the formulation of predictions with regard

to success of acquisition. This type of research has become quite copious, as can be witnessed

in literature reviews found in volumes such as Hansen Edwards and Zampini (2008),

addressing acquisition from the point of view of production and perception, and exploring

didactic implications. By contrast, the transfer and acquisition of external sandhi, phonological processes

that span word boundaries, have been for the most part neglected in L2 speech research.

Beyond the relatively well-known areas of liaison and enchaînement in L2 French (e.g.

Howard, 2008; Shoemaker, 2010; Sturm, 2013), the acquisition of boundary effects in L2

speech remains largely unexplored. Zsiga (2011) notes this gap, and offers a review of

previous research in which only a few studies dealing with a small number of L1-L2 pairings

are discussed (Catalan-English: Cebrian, 2000; English-Russian: Zsiga, 2003; Spanish-

German: Lleo&Vogel, 2004; Korean-English: Zsiga, 2011).

One such sandhi phenomenon is the resolution of vowel hiatus at word boundaries.

This paper examines the acquisition of V#V sequences by Polish learners of English. Polish

and English appear to show systematic differences in the realization of hiatus. Textbook

descriptions of English refer to ‘glide insertion’ and ‘linking/intrusive [r]’ as the preferred

hiatus fillers in traditional vernacular dialects. By contrast, in Polish hiatus is typically

1 This research was supported by a grant from the Polish National Science Centre (Narodowe Centrum Nauki).

Project number 2012/05/B/HS2/04036

2

realized with glottal stops (Dukiewicz and Sawicka, 1995), glottalization, or increases in

spectral tilt (Schwartz, 2013a). Thus, acquisition of L2 English hiatus by Polish learners

entails the suppression of glottalization. This seemingly straghtforward cross-linguistic

difference is complicated by the fact that glottalization of vowel hiatus also occurs in English,

where it functions primarily as a marker of higher-level prosodic constituents (e.g. Dilley et

al., 1996). An additional complication may be observed in recent studies (e.g. Britain and

Fox, 2008; Davidson and Erker, to appear), which suggest that glottalization in English is

increasing in frequency in linguistically diverse urban areas. Nevertheless, since English

pronunciation instruction in Poland and many other countries is based on traditional

vernacular varieties, we shall consider non-glottalized hiatus, produced with modal phonation,

as the target for acquisition. Our study presents production data from 21 Polish students of English performing

both reading and imitation tasks. The reading task is intended to gauge the level of acquisition

of non-glottalized hiatus at the time of the experiment, while the imitation task seeks to elicit

modally produced hiatus by means of phonetic convergence with a model voice (Babel, 2012;

Honorof et al., 2011; Pardo et al., 2012). In addition, we present data from listening tests, in

which L1 English speakers rate modal vs. glottalized tokens on a scale of foreign

accentedness, while non-native speakers assess the comprehensibility of tokens containing

glottalized and non-glottalized hiatus. The production results suggest that suppressing

glottalization is indeed an integral part of L2 phonological acquisition for advanced Polish

learners, and that the production of modal voiced vowel is facilitated by both the imitation

task as well as the lexical frequency of the vowel-initial word. The listening tests revealed that

glottal vs. modal productions in vowel hiatus have greater impact on L1 listeners’ ratings of

accentedness than on L2 learners’ ratings of comprehensibility.

In introducing our experiments and discussing the results, we focus on issues of

phonological representation. In particular, we hypothesize that initial vowels in the two

languages are characterized by a representational difference; in Polish they are more

prominent prosodic entities that show a greater tendency than the corresponding segments in

English to be realized with glottalization. The representational hypothesis is formulated in the

Onset Prominence framework (OP; Schwartz, 2013b), which incorporates the phonetic

ambiguity of the initial portion of vocalic segments in CV sequences. This portion of the

signal, represented as the Vocalic Onset (VO) node of structure, is phonetically vocalic, yet

typically bears cues to the identity of the preceding consonant. We suggest that Polish and

English differ with respect to whether this node of structure is incorporated into the

representation of initial vowels. VO specification is posited for Polish vowels, and is reflected

in the tendency for glottalization and the formation of prosodic boundaries before word-initial

vowels. In English this node is absent, and initial vowels typically acquire an onset via

resyllabification or the ‘insertion’ of linking consonants. The rest of this paper will proceed as follows. We start by providing background on

the phonetics and phonology of vowel hiatus in English and Polish. This is followed by a

description of the production experiment. Then we present a description of the listening tests

that were carried out. This is followed by general discussion on the wider implications of our

study for the field of L2 phonology. Finally, we conclude with a brief clarification of the

phonological approach underlying our hypotheses and the interpretation of the results.

2 Vowel hiatus in English and Polish

This section will present background on vowel hiatus in English and Polish. We start by

considering previous descriptions. This is followed by a presentation of conceptual issues

3

underlying the phonology of hiatus. Finally, we introduce the Onset Prominence framework,

and derive the representational hypothesis underlying the experimental studies.

2.1 Previous descriptions hiatus in the two languages

Phonological descriptions of English hiatus resolution (e.g. McCarthy, 1993) typically refer to

a categorical process of glide insertion (see Ed [sijed], new image [nuwɪmədʒ]; McCarthy,

1993), as well as linking or intrusive /r/ in non-rhotic dialects (Uffmann, 2007). By contrast,

recent phonetic studies cast doubt on the assumed categorical nature of the process. Davidson

and Erker (to appear) present evidence against ‘glide insertion’ by English speakers in New

York City. Glottalization of hiatus is typically observed when the word-initial vowel is

stressed. In other cases, they found that VV and V#V sequences differ systematically from

VjV and V#jV sequences. We are left to conclude that traditional descriptions of ‘glide

insertion’ reflect the segmental transcriptions afforded to earlier authors’ percepts of non-

glottalized vowel hiatus. In other words, non-glottalized hiatus may have been misheard as

containing glides. The descriptions of hiatus found in works with more of an applied or pedagogical

orientation resist classifying ‘glide insertion’ as a categorical phenomenon. Cruttenden (2001)

notes that in vocalic sequences at word boundaries, slight linking glides might be audible, but

they are not as distinct as phonemic glides. He also mentions that linking glides in English

might be substituted with a glottal stop, especially before a vowel in an accented syllable.

Cruttenden also states that the use of glottal stops in English is not as common as in some

other languages, e.g. German, and is limited to emphatic utterances. Lecumberri and

Maidment (2000: 64) see utterance-initial glottal stop insertion in emphatic speech as a

universal phenomenon. Wells (2008: 345) claims that glottalization is optionally used to add

emphasis to syllable-initial vowels or to avoid hiatus in neighboring syllables (V#V).

According to Wells, British English speakers might use a glottal stop to avoid r-liaison.

Roach (2009: 117), in weighing the relative importance of various elements of

English pronunciation, suggests that sandhi processes should be a priority: ‘It would not be

practical or useful to teach all learners of English to produce assimilations; practice in making

elisions is more useful, and it is clearly valuable to do exercises related to rhythm and linking’

(emphasis ours). However, in the chapter on linking he does not address V#V sequences.

Instead, he focuses on linking and intrusive /r/ and the effect of a word boundary position on

the realization of consonantal allophones in pairs such as keep sticking and keeps ticking.

Cook (1991: 66) claims that in English two vowels across a word boundary are connected

with a slight glide, but warns against exaggerating it. Hewings and Goldstein (1999: 91) also

report that speakers join vowels across word boundaries with a ‘very short’ glide to ‘link the

vowels together to make the flow of speech smoother and to avoid a gap between the words’.

On the other hand, a fairly widely used pronunciation course by Lujan (2006) devotes little

attention to C#V linking, without even mentioning hiatus. As might be expected, there has been significantly less written about vowel hiatus in

Polish. In a phonological study, Rubach (2000) suggests that glide insertion is the norm for

word-internal hiatus, though he does not consider word boundaries, and no phonetic data is

presented beyond impressionistic transcriptions. Other descriptions (Dukiewicz and Sawicka,

1995; Gussmann, 2007), suggest that glottal stop insertion, though not obligatory, is the

preferred way of resolving hiatus. This may be observed both at word boundaries and at

word-internal morpheme boundaries. This suggestion is supported by data from Schwartz

(2013a).2 Data from 17 speakers showed a range of realizations from full glottal stops, to

2 Malisz et al (2013) look at initial vowel glottalization in Polish and German, and found a lower rate of

glottalization in Polish than for German. They did not do a comparison with English, though comparing their

4

glottalization realized as non-modal phonation, to drops in pitch and amplitude (cf.

Hillenbrand and Houde 1996). The data showed no signs of anything that might be interpreted

as a ‘glide’. In the most rapidly produced tokens without visible glottalization, the first vowel

in V#V sequences was often elided, while the second vowel was produced with increased

spectral tilt (cf. Sluijter and van Heuven 1996; Crosswhite, 2003). In sum, the literature on vowel hiatus in English and Polish suggests a slightly more

nuanced reality than the categorical claims of glide and glottal stop insertion found in some

phonological studies. Nevertheless, it appears that one systematic generalization may be

made. Modal hiatus appears to be the norm in English, which in earlier descriptions led to the

perception of an ‘inserted glide’. However, glottalization may also be found, typically before

stressed initial vowels. In Polish, glottalization dominates, and modal hiatus still entails the

marking of the initial vowel by means of raised spectral tilt. Thus it appears as if initial

vowels in Polish are more prominent prosodic entities than initial vowels in English. In what

follows, we offer a phonological interpretation of the hiatus phenomena.

2.2 Hiatus resolution – phonological interpretations

Phonological descriptions typically refer to the ‘resolution’ of vowel hiatus. This term

suggests a marked or non-optimal status for V#V sequences, in which the second vowel

violates ONSET, a prosodic constraint against vowel-initial syllables. The most frequent repair

strategies across languages include the coalescence of the vowels, or the appearance of a

consonant between them. Common hiatus fillers include glottal stops and [h]. The glides [j]

and [w] are also common when the first vowel is front or round. In essence, then, the

appearance of consonants in hiatus positions is generally taken to mean the ‘insertion’ of a

consonantal onset, be it a glottal stop, a glottal fricative, a glide, or a linking/intrusive rhotic.

In the parlance of Optimality Theory (Prince & Smolensky, 1993), insertions constitute a

violation of the faithfulness constraint DEP, which punishes output segments that are absent

from input representations.

From a logical standpoint, there is an alternative view on the origins of hiatus filling

consonants. Instead of the insertion of an entity that is absent from the underlying

representation, hiatus consonants may be interpreted as the realization of an entity that is

present in the underlying representation. That is, one may envision hiatus resolution as the

satisfaction of MAX, a faithfulness constraint that punishes the deletion of input features. In

the case of linking [r] in non-rhotic dialects of English (far – far away), this interpretation is

suggested by the presence of the letter r in the orthography. By contrast, other hiatus fillers in

English are generally accepted to be absent from the underlying input representations; their

appearance is assumed to be the result of insertion processes. The same interpretation is commonly applied to the appearance of glottal stops or

glottal marking in hiatus sequences. For example, the well-known process of harter Einsatz in

German, by which morpheme-initial vowels are realized with a glottal attack, is often referred

to as ‘glottal stop insertion’ (e.g. Wiese, 2000). We suggest that in languages in which glottal

marking is relatively common, including German and Polish, its appearance might better be

characterized as the preservation of an underlying element of the phonological representation.

In what follows, we will briefly introduce how this hypothesis is derived within the Onset

Prominence representational environment.

2.3 The OP environment and the representation of initial vowels

results with studies of English (e.g. Dilley et al., 1996) suggests that glottalization is more common in Polish.

Also, they did not specifically address the hiatus context, and they focused on glottalization as a marker of

higher-level prosodic structure in spontaneous speech and prepared (read) speeches.

5

In the OP environment, both segmental representations and prosodic constituents such as

syllables are constructed from the hierarchy in (1), which is derived from the phonetic events

observed in a stop-vowel sequence in initial position.

(1) The CV building block of the Onset Prominence representational hierarchy

Manner of articulation is encoded on the basis of the layers of structure contained by a given

segmental tree. This is shown in (2), which provides structures for a labial stop, nasal,

fricative, approximant, and vowel. The binary nodes are active elements in the individual

representations, while the unary nodes serve as place holders to indicate the relative

hierarchical position occupied by a given segmental structure. The segmental symbols may be

interpreted as shorthand for place and laryngeal specifications.

(2) Manner distinctions in the OP environment

In the hierarchy in (1), the segmental affiliation of the VO node is ambiguous. This single

layer of structure may be claimed by multiple segment types. On its own, VO represents the

class of approximants and glides as in (2). In (2), we also see that VO may be active in the

representation of obstruents and nasals, representing formant transitions that cue consonant

place of articulation (e.g. Wright, 2004). At the same time, the VO node is derived from a

portion of the signal that is phonetically a vowel. As a result, we might expect to find it built

into the representation of vowels as well as consonants. In (3) we see two types of vowel

representation, with or without an active VO node.

(3) Vowels with our without VO specification

6

The presence or absence of VO in vowel representations offers a useful perspective on the

prosodically ambiguous behavior of onsetless syllables across languages (see Schwartz

2013a). Briefly stated, VO-specification allows initial vowels to satisfy prosodic constraints

requiring onset consonants. This may be manifested as an apparent ‘empty consonant’ (e.g.

Marlett & Stemberger, 1983), or simply as prosodic well-formedness for processes such as

stress assignment or reduplication (cf. Downing, 1998 for discussion of prosodically ill-

formed onsetless syllables). With respect to the representation of initial vowels in Polish and English, we propose

VO specification for the former, but not the latter. That is, Polish initial vowels may be

thought of as containing a built-in consonant. One area in which this claim is manifest is in

the greater tendency for glottalization of initial vowels in Polish (Schwartz, 2013a). In

English, glottalization is associated primarily with higher-level prosodic constituents (e.g.

Dilley et al., 1996). Moreover, Polish word-initial syllables have been claimed to bear

secondary stress (Dogil, 1999),3 which in the case of initial vowels suggests a prominent

prosodic status as represented by the VO node in OP structures. The OP perspective on vowel hiatus is revealed when we look at the mechanisms by

which segmental structures combine into prosodic constituents. Consider (4). On the left we

see individual segmental structures for English cry, while on the right we see the word as a

single prosodic constituent. The fundamental process at work here is called absorption, by

which lower-level vowel and sonorant structures are fused with the higher level obstruents

that precede them. In cry, the vowel is absorbed into the rhotic, which is in turn merged with

structure of the initial stop. The absorption process shown in (4) is prosodically motivated. Without it, individual

segments such as /r/ or /k/ in cry would be forced to stand alone as prosodic constituents.

Absorption thus implies the presence of a minimality constraint for well-formed syllables.

Such a constraint combines two commonly invoked restrictions on syllable structure, both of

which are satisfied by means of absorption. The requirement for onset consonants is satisfied

by absorbing /aɪ/ into the structure of the rhotic, while a constraint against syllabic obstruents

is alleviated when the rhotic-vowel sequence merges with the /k/.

(4) Segmental and constituent (right) structures for English cry

When two OP vowel structures are adjacent, absorption may not take place since the

two trees are at the same level of the hierarchy. In such cases, a different mechanism,

submersion, may be motivated to ensure prosodic well-formedness. This is shown in (5). The

two trees on the left show a /ua/ sequence. The second vowel may not be absorbed, since the

structure to its left is not higher in the hierarchy. Instead, it is submerged under the first tree,

3 Newlin-Łukowicz (2012) found minimal acoustic support for Dogil’s claim. However, she did not measure

spectral balance, an established cue to prominence in many languages (Sluijter & van Heuven 1996, Plag et al.

2011) including Polish (Crosswhite, 2003).

7

producing the single structure /ua/ that we see in the third tree from the left. Such a sequence

may be perceived as [wa], yet its labial element is distinct from the lexical glide /w/ (the

rightmost tree), in which it is housed at the VO level. This representational distinction

captures the phonetic differences between underyling and hiatus glides observed by

Cruttenden (2001), and Davidson and Erker (to appear), as well as phonological differences in

other languages (cf. Levi, 2008).

(5) Submersion of the second vowel in a VV sequence

In (5), we see that submersion prevents the formation of a boundary at vowel hiatus.

Submersion is also the process that we claim as the origin of vowel quantity and weight

distinctions, which are a generally accepted feature of English, but are unattested in Polish.

When the second vowel in V#V sequences is specified with the VO, as we claim for Polish,

submersion is not motivated since the VO-specified vowel is already a well-formed prosodic

constituent. As such, it may be strengthened by means of promotion (Schwartz, 2013b), a

fortition process by which VO-specified vowels and approximants are raised to the highest

level of the OP hierarchy normally occupied by stop closure. Promoted vowels show a greater

tendency to be realized with glottalization. When glottalization is not produced, their

prominence may be preserved by increases in spectral tilt (Schwartz, 2013a). Beyond the mechanism shown in (5), submersion is a process with far-reaching

prosodic implications, offering additional insight into the behavior of consonants in both VC

and VCV contexts, with deeper predictions for the form and behavior of larger prosodic

constituents. We will return to submersion in the General Discussion section, considering its

implications for the study of L2 speech.

3 Experiment 1 – hiatus production in reading and shadowing tasks

The phonological considerations discussed above lead to a hypothesis that L1 Polish

interference may result in a tendency for glottalization of vowel hiatus in the speech of Polish

learners of English. To test this hypothesis we conducted an experiment in which we elicited

data from learners producing English V#V sequences. We compared learners from two groups

and in two tasks, reading and imitation. We hypothesize that glottalization will be more

prevalent in the speech of less advanced learners, and in the reading task. If these hypotheses

are supported, it may be taken as evidence in favor of representations for English that are

conducive to linking of V#V sequences, and Polish representations that favor glottalization as

a hiatus filler. The reading task may be assumed to provide information about the state of acquisition

at the time of recording, while the imitation task offers some perspective into learners’

potential for acquisition. In recent years, phonetics research has investigated the performance

of L1 speakers in shadowing tasks. The features that have been found to undergo phonetic

convergence include fundamental frequency (Goldinger, 1997), VOT (Shockley et al., 2004),

and vowel quality (Pardo et al., 2012). This research has investigated the role of episodic

8

memory (Goldinger, 1998) with the goal of testing exemplar-based models of speech

perception (e.g. Johnson, 1997). Findings of phonetic convergence with model productions in

shadowing tasks may be said to support the hypotheses of exemplar-based perception, insofar

as such productions reflect how they were perceived.

As yet, experiments employing the imitation paradigm have been largely limited to L1

speech. However, it is not difficult imagine the benefits of using imitation study in L2

phonological research. Repetition, of course, has always had a prominent position in foreign

language pronunciation instruction. This fact suggests a parallel with L1 phonetic

accommodation. At the same time, one might expect L1-based perceptual constraints (Best,

1995; Best and Tyler, 2007) to hinder L2 speakers’ convergence with a native stimulus. The

question that remains is to what extent these constraints may be overridden in shadowing

tasks. In a series of experiments investigating problematic areas for Polish learners of English,

Rojczyk (2012, 2013) and Rojczyk et al. (2013) found evidence of phonetic convergence in

VOT, formant frequencies of the vowel /æ/, and the suppression of coda stop release. In the

current study, we seek to build on this research and investigate the extent to which shadowing

facilitates Polish learners’ suppression of vowel glottalization in hiatus sequences.

Participants

Twenty one Polish learners of English participated in the experiment. All were majors in

English studies at either the University of Silesia (UŚ) in Sosnowiec or Adam Mickiewicz

University in Poznań (UAM). The 21 students comprised two groups. The first group (N=12)

included first year students, while the second group (N=9) was made up of students in higher

years. None had spent more than three months in an English-speaking country.

The division into the two groups is motivated as follows. In the first year of English

studies in Polish universities, students receive intensive pronunciation instruction (2*90

minutes/week). In the second year, this instruction is reduced to one meeting a week, while

students in the third year and above no longer receive explicit instruction in pronunciation.

The first year group had completed one semester of instruction at the time of the recordings.

The higher years’ group had completed a minimum of three semesters. The first two

semesters of instruction concentrate on segmental features. Word boundary effects receive a

small amount of attention, but only in the second year. Thus, it may be assumed that the first

year group was unfamiliar with sandhi processes associated with English V#V sequences,

while the higher years’ group had some awareness of these phenomena.

Materials

Data were elicited from student productions of an English sentence list containing 26 V(r)#V

sequences.4 The list of target sequences may be found in Appendix 1. The stimuli also

contained fillers, as well as tokens used in a separate experiment. The recordings were made

in soundproof recording studios in the English departments at each of the two universities.

The studios were equipped with a computer monitor upon which the stimulus data were

presented. In the first task, subjects were instructed to read the sentence presented on a slide

in a Power Point presentation. In the second task, the presentation of the slide was

accompanied by an audio recording of one of five native speakers of English (2 US English

speakers, 3 British English speaker) producing the stimulus. Students were instructed to

repeat after the model voice, which in each case produced the V#V sequence without visible

glottalization. The imitation task was performed immediately after the reading task. The

4 Three of the tokens contained a Vr#V sequences in which ‘linking’ /r/ may be expected in non-rhotic dialacts.

One target token contained the context for ‘intrusive’ /r/.

9

students received course credit for their participation. A total of 1092 tokens were obtained

(26 items * 2 tasks * 21 speakers).

Analysis

The V#V tokens were inspected with the help of the Praat program (Boersma & Weenink,

2011) with the aim of establishing the likelihood of modal and glottalized realizations of the

target sequences. Despite variation in the realization of glottal events (cf. Redi & Shattuck-

Hufnagel, 2001), preliminary analysis allowed us to establish three categories for vowel

realization. These categories are illustrated in Figures 1-3. Modally voiced hiatus is

exemplified in Figure 1, showing the V#V sequence in saw everything.

Figure 2 provides an example of a glottalized token in the sequence stay out. The selected

portion of the display reveals a creaky voice quality that is visible as a period of irregularity in

the periodicity of the vowel wave.

In Figure 3, we see a full glottal stop in the production of English see all. The selected portion

of the display is characterized by silence associated with full glottal closure.

10

Hillenbrand & Houde (1996) revealed that local drops in pitch and amplitude of modally

produced VV tokens may be perceived as glottal stops. Our tokens included a small

percentage of such cases. However, because of difficulties involved in the quantification of

such drops in amplitude and pitch, such tokens were coded simply as modal. Thus, a small

number of the tokens categorized as modal may have been realized with a feature associated

with the perception of glottalization. The annotation was performed by three out of the four authors of this paper. Of the 21

speakers, 19 were analyzed by a single annotator. The other two speakers were analyzed by

all three annotators to calibrate the analysis and check for consistency. With regard to the

coding of the initial vowels, the calibration analyses revealed a high level of agreement in the

case of tokens coded as modal (unanimous agreement in 90.5% of cases; Fleiss’ Kappa = 0.78

for two categories, modal vs. non-modal). When all three categories were included, some

discrepancies arose in the choice between tokens coded as glottalized and those containing a

full glottal stop (complete agreement in 61% of cases; Fleiss’ Kappa = 0.54 for the three

categories). Tokens for which two out of three annotators agreed were assigned to the

category selected by the majority. In the rare cases in which the three annotators assigned

tokens to three different categories, the first author made the final decision.

Results

The first results we will present are focused on the reading task, with the aim of characterizing

the participants’ level of acquisition of modal-voiced hiatus at the time of the experiment. The

vowel realizations for the reading task for both learner groups are summarized in Figure 4.

The 1st year group produced modal hiatus in 35.6% of the tokens, compared to 47% for the

higher years’ group. The 1st year group also produced a noticeably higher percentage of full

glottal stops (34.6% vs 22.2%). Two binary logistic regression analyses were carried out on

the reading data (for the full tables of all the regression analyses, see Appendix 2). The first

analysis examined modal tokens (yes or no) as the dependent variable while the second

analysis looked at full glottal stops (yes or no). In both cases, learner group, lexical frequency,

5 and sex were posited as covariates. The results revealed that learner group (higher years; B=

.440, p=.016) and lexical frequency (B=.675; p<.001) were significant predictors of modal

voice in hiatus tokens. The second analysis, with glottal stops as the dependent variable,

revealed that the higher years’ group was less likely to produce full glottal stops (B= -1.128,

p=.001). Significant effects were also found for female speakers (B=1.059, p=.03) and higher

frequency words (B= -.653, p=.001).

5Token frequency was coded on a three point scale according to the Francis-Kucera corpus. Values below 120

were categorized as ‘least frequent’, from 121-240 was ‘more frequent’, and above 240 was ‘most frequent’.

11

Figure 4 – Reading task results for the two learner groups

A graphic summary of the results for the imitation task across learner groups is given in

Figure 5. Again, two binary logistic regression analyses were carried out with modal voice

and glottal stops as dependent variables, and the same covariates as in the previous analyses.

The advanced group was again more likely to produce modal tokens (76.9% vs. 68.9%; B=

.482, p= .02), however the constant was not significant (B= .369, p=.149), suggesting that the

imitation task attenuated the differences between learner groups with respect to the likelihood

of modal realizations. With regard to glottal stops, all of the covariate effects (frequency,

learner group, sex) were significant. The higher years’ group was less likely to produce glottal

stops in the imitations (B= -1.128, p=.001). Glottal stops were also less likely in higher

frequency words (B= -.653, p=.001), and more likely for female speakers (B= 1.059, p=.03).

Figure 5 Imitation task results for the two learners groups

We now turn to a presentation of the results in which we compare the effects of the

independent variables only with regard to the percentage of modal voiced tokens, which are

considered as the target realizations of the hiatus sequences. In other words, the following

tables may be said to assess the likelihood of native-like realization of the word-initial vowel.

Overall 56.4% of the tokens across learner groups and tasks were realized with modal voice.

0,00%

5,00%

10,00%

15,00%

20,00%

25,00%

30,00%

35,00%

40,00%

45,00%

50,00%

G-Stop Glottalized Modal

1st yr

higher years

0,00%

10,00%

20,00%

30,00%

40,00%

50,00%

60,00%

70,00%

80,00%

90,00%

G-Stop Glottalized Modal

1st year

Higher years

12

Figure 6 presents the percentage of modal tokens for the two tasks across both learner groups.

In the reading task 41% of the hiatus tokens were produced with modal voice, while this rate

increased to 73% in the imitation task.

Figure 6 – Percentage of modal voiced tokens across both learner groups

Figure 7 separates this result in terms of learner group. We can see a slight tendency for

higher rates of modal realization for the advanced group across tasks. The difference between

the two groups was greater in the reading task (47% vs. 35.6%) than in the imitations (77%

vs. 68.9%).

Figure 7 – Percentage modal tokens for tasks and group

Figure 8 shows the percentage of modal tokens as a function of token frequency across learner

groups and task. We can observe a pattern by which more frequent vowel-initial words are

more likely to be realized with modal voice

41%

73%

0%

10%

20%

30%

40%

50%

60%

70%

80%

Reading Repetition

%Modal Voice

0,00%

10,00%

20,00%

30,00%

40,00%

50,00%

60,00%

70,00%

80,00%

90,00%

read imitate

1st years

Higher years

13

Figure 8 – Percentage of modal tokens as a function of lexical frequency of vowel-initial word

With task was included as a covariate, a binary logistic regression analysis with %Modal as

dependent variable revealed that task (imitation; B = 1.462, p < .001), lexical frequency (B =

.539, p < .001), and learner group (Advanced; B = .462, p = .001) all were significant

predictors of modal productions, while sex was not (Female; B= -.231, p=.151).

Finally, Figure 9 presents the number of modal tokens (maximum 26) for each

individual speaker in the reading and imitation tasks. As might be expected, in each case the

imitation task elicited more modal productions.

Figure 9 – Individual results for modally produced hiatus tokens

Discussion

The results of the production study may be summarized as follows. The likelihood of target-

like modal realization of V#V sequences was greater for the higher years’ group, which

suggests that the acquisition of modal hiatus is facilitated to some extent by the pronunciation

0%

10%

20%

30%

40%

50%

60%

70%

80%

leastfrequent morefrequent mostfrequent

LexFreq %Modal

0

5

10

15

20

25

30

read

imitate

14

instruction these learners had received at their universities. We attribute vowel glottalization

to L1 phonological interference. Modal hiatus was also facilitated by the lexical frequency of

the vowel-initial word, as well as the imitation task, and to a small degree the sex of the

speaker. These additional results, which may be claimed to be attributable to non-

phonological factors, present a fundamental theoretical challenge: to tease apart the

phonological and non-phonological aspects of hiatus glottalization. We shall discuss each of

these factors in turn. The lexical frequency effect may be conceptualized in terms of Lindblom’s (1990)

H&H theory, according to which speaker behavior is governed by the need to minimize

articulatory effort, while at the same time producing sufficient discriminability. Glottalization

is perceptually salient and increases discriminability, yet entails increased effort of additional

laryngeal gestures. According to Lindblom, higher frequency words will be recognized even

with reduced discriminability, so these words are still recoverable with modal hiatus that is

produced with lesser articulatory effort. The next result we take up is the effect of the imitation task. While shadowing elicited

a much higher rate of target-like modally voiced hiatus realizations, the task attenuated to

some extent the difference in performance between the two learner groups. This result could

perhaps be interpreted as an indication of greater effects of repetition in early stages of

acquisition. That is, the 1st year group showed greater improvement in their imitations. In

accordance with previous studies involving shadowing, it is possible that phonologically-

induced perceptually constraints are overridden by the task. The greater impact of imitation

for 1st year students may also find a parallel in novelty effects found for early learners (e.g.

Chang, 2012). A related study on C#V sequences in Polish English (Schwartz et al., 2013)

found that imitation had a larger impact on first year learners’ productions. The implications

of these findings, however, are not entirely clear. It could be that the first year group showed

greater improvement simply because they had more ‘room’ to improve. The final variable that we examined was the sex of the speaker. In American English,

studies have shown that females have a greater tendency to use creaky phonation for non-

linguistic purposes (Yuasa 2010). In our study, females were somewhat less likely to produce

modal-voiced hiatus, and were more likely to produce full glottal stops. However, on the basis

of our results, we cannot make any firm conclusions with regard to the use of non-modal

phonation as a function of sex.

The factors affecting the likelihood of glottalization in our study, in particular lexical

frequency and the shadowing task, are compatible with usage-based or exemplar-based

models of phonology and speech perception (Johnson, 1997; Bybee, 2001; Pierrehumbert,

2001). In such models, episodic memory traces play an instrumental role in the formation of

phonological categories such as segments and syllables. These categories are not primitives,

but rather emergent properties that form on the basis of auditory input. An important

assumption of exemplar theory is that gradient phonetic detail is recorded in each exemplar of

a category, and is therefore an integral part of category representation. This is to be expected

given the role of episodic memory in the hypothesized mechanism of category development.

Assuming the validity of the exemplar approach, one may therefore suggest that the putative

extra-grammatical effects observed in the present study are indeed phonological. The question

that remains concerns the compatibility of exemplar models with the representations proposed

upon which our research hypothesis is based. One issue that exemplar theory has not, to our knowledge, explicitly addressed is the

representational nature of emergent phonological categories. In other words, it is not stated

what the exemplars are exemplars of. The Onset Prominence model seeks to fill this gap. The

OP environment is derived from a hierarchy of phonetic events that is an integral part of the

auditory input for every user of spoken language. In this input, the phonetic properties

15

associated with manner of articulation provide auditory structure, providing a locus for

gradient phonetic details associated with place and laryngeal features. We suggest that the OP

representational hierarchy is indeed compatible with exemplar-based models. The benefit of

these representations for exemplar theory lies in the fact that they provide specific predictions

about the relative perceptual role of different types of gradient phonetic detail. In the case of

place and laryngeal cues, phonetic detail defines boundaries between categories. By contrast,

the perception of manner appears to be privative in nature. For example, a stop may be

produced with incomplete closure (Crystal and House, 1988), but this does not necessarily

imply the presence of sufficient frication noise to induce the perception of a separate manner

category (fricative). While questions about the phonological status of hiatus realization constitute one part

of our study, there is an additional important question that must be considered. In particular,

the glottalization of vowels has not been the focus of a large number of L2 studies,

presumably since its phonological status is not universally acknowledged. In a related study

of C#V sequences in the speech of Polish learners of English, Schwartz et al. (2013) looked at

the interaction between glottalization and final devoicing. Final devoicing, of course, is an

‘established’ feature of Polish-accented English and a major focus of pronunciation

instruction. Glottalization of hiatus, on the other hand, is not so intimately connected with

familiar segmental errors. Thus, the consequences of hiatus glottalization for the perception of

L2 English are not obvious. We seek to address this question by means of listening tests

described in the following section.

4 Experiment 2 - Accentedness and comprehensibility of glottalized and modal hiatus

The aim of this experiment was to assess the effect of vowel hiatus realization on the

perceived comprehensibility and accentedness of non-native speech (cf. Derwing & Munro,

1997; Munro, 2008). To explore the relationship between these variables, two separate on-

line listening tests were carried out. In the first, directed at L1 speakers of English, listeners

rated the foreign accentedness of glottalized and modal tokens. In the second, distributed to

Polish learners of English, participants rated the comprehensibility of glottalized and modal

tokens.

4.1 Participants and stimuli

Two groups of participants took part in the experiment:

1. 31 native speakers of Polish (for the comprehensibility test)

2. 41 native speakers of English (for the accentedness test) Data on the participants’ knowledge of English, exposure to non-native accents of English as

well as other known languages were collected, but proved not to have any significant effects

in relation to the aims of the study and therefore will not be reported on. The experimental stimuli were taken from recordings obtained in the production study.

Each stimulus consisted of utterances of between three and seven words. The total number of

tokens used was 36. Out of these, 12 pairs (i.e. 24 tokens) contained non-native utterances

with vowel hiatuses. That is, each member of the pair was the same utterance, but one was

produced with a modal realization of the hiatus, while the other had a glottalized realization.

The tokens were checked by two professional pronunciation teachers for additional

segmental errors. Four glottalized tokens were judged to contain additional pronunciation

errors, while three tokens with modal realization were found to exhibit additional errors.

Appendix 3 provides a summary of the utterance pairs and errors identified. Aside from the

16

12 pairs, the stimuli contained six additional tokens of native English utterances taken from

target recordings used for the repetition task in the production study. Finally, six other non-

native without vowel hiatuses were used to act as distractors.

4.2 Procedure

Two perception surveys were created for the purposes of the study. One survey was designed

to study how easily native speakers of Polish would comprehend the stimuli, while the other

examined the degree of accentedness perceived by native speakers of English. The surveys

were built using the Google Forms software and were additionally customized by hand to

include audio files and additional data validation. The surveys were made available online and

distributed using their URL addresses. Cooke et al. (2013) discuss the merits and drawbacks

associated with web-based speech perception studies. We feel that the merits outweigh the

drawbacks. One advantage is the highly voluntary nature of the participants. Another

advantage is the feasibility of recruiting a large number of L1 English listeners in a non-

English speaking country, particularly those who do not have everyday experience with

Polish-accented English. Nevertheless, we are in the process of attempting to replicate this

study in an on-site experiment. Both surveys consisted of two parts. The first part was comprised of a short linguistic

background questionnaire that was followed by the second part in that included perception

tasks. Each perception task contained a recording and a question to answer, i.e. ‘Which of the

descriptions below best describes the speaker's pronunciation?’. The task was to answer the

question by choosing one of the five available options. In the comprehensibility survey, the

listeners had to rate how well they understood the utterances (5 – very easy to understand; 1 –

very difficult to understand). In the accentedness survey, the listeners rated the degree of non-

native accent in the utterances (5 – clearly native; 1 – clearly foreign). All descriptions and

instructions in both surveys were delivered in English.

While completing the surveys listeners could not compare two recordings to each

other. Only one question could be viewed at a time and the participants could not continue to

the next question without first answering the current one. It was also impossible to return to a

previously answered question. The participants could only rely on their own impressions

when making perception judgments. In addition, each survey attempt was unique in the sense

that the order of all perception tasks was randomized when the survey was accessed. This

helped limit the effect of question order on the responses. As mentioned above, the experiment was conducted via the internet. Consequently, the

participants completed the tasks remotely on their own computers. The surveys were

distributed among the participants using the following URL addresses:

http://goo.gl/uWNDGZ (comprehensibility study) http://goo.gl/Hsypq7 (accentedness study)

Each participant was instructed to complete the survey only once and to use headphones to

listen to the stimuli in order to ensure sound fidelity. All participants were unaware of the

purpose of the experiment.

When participants accessed the surveys they were first asked to provide information

about their linguistic background and then they moved on to the experiment proper that

consisted of 36 perception tasks. No indication of this division was given to the participants. When completing the surveys, the participants were presented with only one question at a

time. In each question, the participants were instructed to do the following:

1. Click on a play button and listen to a short recording of an utterance. The recordings

could be replayed if needed.

17

2. Answer the question by choosing one of the five available options numbered 1–5. The

participants could not proceed without first answering the current question. No

feedback was presented for answering a question. 3. Click on ‘next’ to continue to the next question.

The participants continued until they answered all the questions. At this point, the ‘submit’

button became active and the listeners could click on it to send their responses. A

confirmation screen concluded the experiment.

4.3 Data Analysis

A total of 2628 responses were obtained in the experiment (comprehensibility survey: 36

tokens * 31 listeners = 1116; accentedness survey: 36 tokens * 42 listeners = 1512). The 438

responses to filler tokens without vowel hiatuses were excluded from the analysis. The

remaining 2190 responses (comprehensibility = 930; accentedness = 1260) were used to

calculate the mean values of comprehensibility and accentedness ratings for each participant.

The means were then analyzed by taking into account the following factors: Realization (whether the hiatuses in the utterance tokens were produced with a non-

native glottal or modal realization or were produced by a native speaker, i.e. had a

native modal realization) Other errors (whether the stimuli contained other errors that could influence the rating

or not) The mean comprehensibility and accentedness rating values for all stimuli types (glottal vs.

modal vs. native) were calculated and compared using a repeated measures ANOVA to

determine the effect vowel hiatus realization (glottalized vs. modal vs. native) on

comprehensibility and perceived accentedness of speech. In addition, the same means and

statistical analyses were obtained for tokens with and without other pronunciation errors in

order to evaluate the effects of these errors on the listeners’ judgments.

4.4 Results

The mean values of the perceived comprehensibility and accentedness ratings for all three

stimuli types are presented in Figure 10. The mean value of the comprehensibility rating was

almost exactly the same for glottalized tokens (M = 4.21, SD = .47) and modal tokens (M =

4.22, SD = .41). Slightly higher comprehensibility ratings were assigned to tokens produced

by native speakers of English (M = 4.51, SD = .48). As for the mean values of the

accentedness rating, the lowest score was found for glottalized (M = 2.23, SD = .47), followed

by modal tokens (M = 2.96, SD = .52). Tokens produced by native speakers obtained the

highest scores for accentedness (M = 4.51, SD = .56).

18

Figure 10. Mean ratings of perceived Comprehensibility (left) and Accentedness (right) of

glottalized, modal and native tokens.

A repeated measures ANOVA was conducted with the mean Comprehensibility and

Accentedness as the dependent variables and the hiatus realization (glottalized vs. modal vs.

native) as the independent variable. The results of the analysis are discussed below. For the perceived comprehensibility rating means (N = 31), Mauchly’s test revealed

that the assumption of sphericity had been violated, χ2(2) = 31.12, p < .001. Consequently,

degrees of freedom were corrected using Greenhouse-Geisser estimates of sphericity (ε =

.60). The results demonstrate a significant effect of hiatus realization on perceived

comprehensibility of an utterance, F(1.20, 36.18) = 9.78, p = .002. A post-hoc Bonferroni test

indicated that the perceived Comprehensibility was significantly different between glottalized

and native tokens, p = .02, as well as between modal and native tokens, p = .001. No

statistical difference was observed between glottal and modal tokens, p > .05. These results

suggest that Polish listeners found all non-native utterances equally comprehensible,

regardless of whether they were produced with a glottalized vowel hiatuses with modal vowel

hiatuses. However, both types of non-native utterances were less comprehensible than

utterances produced by native speakers of English. The analysis of the means of accentedness ratings (N = 42) also showed violation of

sphericity in Mauchly’s test, χ2(2) = 31.36, p < .001. In this case, degrees of freedom were

also corrected using Greenhouse-Geisser estimates of sphericity (ε = .65). A significant effect

of hiatus realization on perceived accentedness of an utterance was found, F(1.30, 53.13) =

257.25, p < .001. Significant differences between all pairs of token types were found in post-

hoc Bonferroni tests, p < .001. The results indicate that when L1 English listeners were asked

to assess the degree of non-native accentedness of utterances, judgments were affected by the

way vowel hiatus was realized. Specifically, the results suggest that non-native utterances

with glottalized vowel hiatuses are perceived as the most foreign by native speakers of

English, followed by non-native utterances with modal realizations. Utterances produced by

native speakers were perceived as the least foreign. Since some of the non-native tokens were judged to contain additional pronunciation

errors, we carried out an additional analysis to investigate whether the results reported above

were indeed due to vowel glottalization rather than other factors. Specifically, mean values

were obtained for non-native glottalized and modal tokens with and without other errors to

determine whether the same trends would be identified for utterances without errors and to

explore the effect of other errors on listeners’ judgments.

The mean values of the perceived comprehensibility and accentedness ratings for

glottalized and modal tokens with and without other are shown in Figure 11Figure . As far as

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

4,5

5,0

Glottalized Modal Native

mea

n C

om

preh

en

sib

ilit

y r

ati

ng

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

4,5

5,0

Glottalized Modal Native

mea

n A

ccen

ted

ness

ra

tin

g

19

the comprehensibility rating is concerned, in the case of tokens without other errors similar

means were observed for both glottalized tokens (M = 4.44, SD = .45) as well as modal tokens

(M = 4.30, SD = .43). The same can be said about tokens with other pronunciation errors i.e.

the differences between the means for glottalized (M = 3.62, SD = .68) and modal tokens (M =

3.81, SD = .65) were small. However, both were lower than the means of tokens without

errors. With regard to accentedness rating, glottalized tokens without other errors were given

much lower scores (M = 2.29, SD = .53) than modal tokens without pronunciation errors (M =

3.13, SD = .51). When both token types contained other pronunciation errors, the difference

was smaller but still noticeable (glottalized: M = 1.92, SD = .57; modal: M = 2.35, SD = .66).

Figure 11.Mean ratings of perceived comprehensibility (left) and accentedness (right) of

glottalized (dark grey) and modal (light grey) tokens.

The statistical analysis involved a paired-samples T-Test being carried out for

measures of comprehensibility and accentedness with a number of within-subject conditions.

The values for tokens without other pronunciation errors were compared in order to confirm

whether the same tendencies could be attested as for all analyzed tokens. The test indicated

that the difference between glottalized (M = 4.43, SD = .49), and modal tokens (M = 4.30, SD

= .43) was not significant for the measure of comprehensibility, t(30) = -2.03, p > .05.

However, in the case of accentedness rating, significant differences between glottalized (M =

2.29, SD = .53) and modal tokens (M = 3.13, SD = .50) were found, t(41) = 13.07, p < .001.

These results match the ones reported above, confirming that glottalized utterances were

perceived as more foreign accented by native speakers even when there were no other

pronunciation errors involved. The same analyses were conducted for tokens with other pronunciation errors. This

time, significant differences were found between glottalized (M = 3.62, SD = .68) and modal

tokens (M = 3.81, SD = .65) for comprehensibility ratings, t(30) = 2.29, p = .029. These

results suggest that pronunciation errors were more prominent in glottalized tokens, leading to

difficulties in comprehensibility. That is, there may be a correlation between the production of

glottalized hiatus and the production of other errors that influence comprehensibility. In the

case of accentedness, significant differences were found between glottalized (M = 1.92, SD =

.57) and modal tokens (M =2.35, SD = .66), t(41) = 4.00, p < .001. This implies that vowel

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

4,5

5,0

without other error(s) with other error(s)

mea

n C

om

preh

en

sib

ilit

y r

ati

ng

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

4,5

5,0

without other error(s) with other error(s)

mea

n A

ccen

ted

ness

ra

tin

g

20

glottalization continued to play a crucial part in in increasing the foreign accentedness of even

in comparison to modal tokens containing other foreign accent features. The effect of the glottalization of vowel hiatus on foreign accent perception is further

evidenced when the scores for tokens without other errors and for tokens with other

pronunciation errors are compared. A paired samples T-Test demonstrated a significant

difference in comprehensibility between glottalized tokens without other errors (M = 4.44, SD

= .45) and modal tokens with pronunciation errors (M = 3.81, SD = .65), t(30) = 8.08, p <

.001. Errors in modal tokens seemed to significantly impact the ease of understanding the

utterances and could be therefore interpreted as being more prominent. However, the same

test revealed that the difference between mean accentedness scores for glottalized tokens

without other errors (M = 2.29, SD = .53) and modal tokens with errors (M =2.35, SD = .66),

were non-significant, t(41) = -.62, p > .05. These results indicate that while the errors in

modal tokens could have impacted comprehensibility, the glottalization of vowel hiatus, even

alone, was just as indicative of foreign accents as the pronunciation errors in modal tokens.

4.5 Discussion

On the whole, the results of the listening tests revealed greater consequences of glottal vs.

modal hiatus for accentedness ratings than for comprehensibility ratings. This is seen in

significant difference in listener ratings between modal and glottal tokens for accentedness,

but not for comprehensibility. Indeed, the high scores for comprehensibility suggest a ceiling

effect by which all the tokens were relatively easy to comprehend. The relatively high

proficiency in English of the Polish speaking respondents probably contributed to this result.

Only three of the Polish participants rated their level of English as intermediate or below, the

remainder were advanced or proficient. In the future we are planning identification and

discrimination tasks to test intelligibility, which we feel will better assess the perceptual

consequences of vowel hiatus realization (see Munro, 2008).

Despite the apparent ceiling effect, there are a few interesting patterns to be observed

in the comprehensibility ratings. The first is that the native tokens were rated as the easiest to

understand. One might expect modally produced hiatus to have detrimental effects on the

comprehensibility of native speech for non-native listeners. English sandhi processes are

associated with a less salient word boundary. According to Cebrian (2000), L2 learners are

subject to a Word Integrity constraint, by which they are predicted to be relatively insensitive

to L2 sandhi processes. Assuming the validity of the Word Integrity hypothesis, the

comprehensibility ratings for the native tokens may come as a surprise. It is possible that the

high proficiency level of the respondents is an indication that they have overcome the Word

Integrity constraint, and the high ratings reflect the absence of other segmental errors.

Alternatively, the Word Integrity hypothesis needs to be reassessed (see Zsiga, 2011 for

evidence and arguments against Word Integrity). Although the differences in comprehensibility ratings between modal and glottalized

tokens were not significant overall, in the case of tokens containing additional segmental

errors, those with glottalized hiatus were rated as more difficult to understand than those with

modal hiatus. While the presence of other errors makes it impossible to claim that

glottalization was the primary factor influencing the ratings, this result could suggest an

overall correlation between glottalization and the presence of other segmental errors in the

speech of L2 learners. Further work is underway to investigate this possibility. With regard to accentedness ratings, our results point to a more direct effect of hiatus

glottalization. Overall glottalized tokens were rated lower than modal tokens (2.23 vs 2.96).

These differences held in tokens both with and without other segmental errors. Interestingly,

the magnitude of this difference was greater in the case of the tokens without additional

21

errors. Such tokens may be claimed to have isolated the effects of the glottalized hiatus

realization. Finally, in the accentedness ratings, modal tokens with other errors were judged

the same or even slightly more native-like (2.35) than glottalized tokens without other errors

(2.29). This finding suggests that L1 English listeners are particularly sensitive to target-like

boundary realization in making accentedness judgments.

5 General Discussion

We turn now the wider implications of our study for the study of L2 phonology. In particular,

we consider issues of phonological representation, investigating the question of ‘what’ is

acquired in L2 speech acquisition. Our experiments have explored a hypothesis that cross-

language differences in the representation of initial vowels govern the placement of a prosodic

boundary in V#V sequences in Polish and English, and that these differences may surface in

the speech of Polish learners of English. In the Onset Prominence framework, Polish initial

vowels are posited as inherently more prominent prosodic entities than initial vowels in

English. As a consequence, they show a greater tendency to be realized with glottal marking

that preserves the salience of the second vowel in V#V sequences. By contrast, in traditional

vernacular dialects of English, prosodically weaker vowels may be joined with the preceding

constituent and are realized without any changes in phonation type.

At this point we consider further implications of the representational differences we

claim underlie the realization of vowel hiatus in the two languages. The key parameter of

submersion was introduced in Section 2 in the context of vowel hiatus. In 5.1, we shall see

that this parameter may extend further into cross-language phonological comparison, unifying

descriptions of vowel hiatus, vowel lengthening, and the behavior of consonants in VC and

VCV contexts. In applying the representational devices of the OP environment to the study of

L1-L2 phonological interaction, we also note the implications of a framework in which

segments and prosodic constituents are constructed from the same representational materials.

Many riddles of interlanguage phonology appear to reside in the gaps between segmental and

prosodic interference. In 5.2 we apply the OP perspective to one such problem: perceptual

epenthesis after coda consonants by Korean learners of English (de Jong & Park, 2012).

5.1 Implications of submersion.

The process of submersion was introduced in (5), which illustrated how adjacent vowel

sequences may merge to form long vowels within words, as well as modal hiatus at word

boundaries. Submersion is a process with far-reaching prosodic implications. It is a form of

phonological recursion of the type proposed by van der Hulst (2010). In his view, coda

consonants may be seen as ‘syllables inside syllables’. In the OP environment, submersion

unifies this view of codas with the representation of long vowels. Additionally, submersion

offers insight into the behavior of consonants in both VC and VCV contexts, with deeper

predictions for the form and behavior of larger prosodic constituents. Let is consider first the behavior of coda consonants. In (6), we see a string of

segmental structures for the English word click. Due to its high position in the

representational hierarchy, the final /k/ may not undergo absorption into the preceding

constituent. To satisfy prosodic prohibitions on syllabic stops, the /k/ is submerged under the

preceding vowel. On the left we see the string of segmental structures, on the right we see the

syllabified form.

(6) Submersion of final /k/ in English click

22

Polish has borrowed the word click, reproducing it as klik, shown in (7).

(7) Polish klik (left) and English click

On the right, the final stop in English click is submerged under the preceding constituent. On

the left the final /k/ in Polish klik is not submerged. In Polish, restrictions against syllabic

stops are satisfied by adjoining the coda to the preceding constituent at a higher level of

structure. From the representations in (7), it is predicted that coda stops in Polish and English

should behave differently. Indeed, in the two languages there is a systematic difference in the

behavior of the final /k/ with regard to the release of the stop. In Polish the release is

obligatory (Dukiewicz & Sawicka 1995), while in English it is frequently suppressed. The

English coda is in a lower prosodic position in the OP hierarchy. Associating lower

hierarchical levels with prosodic weakness, we should expect the English coda to be subject to

lenition processes such as the suppression of release. Submersion appears to be obligatory in

English, as evidenced by the restriction that stressed syllables either contain a long vowel or

coda consonant. Submersion in English is not limited to individual segments – entire syllables may also

be lowered under the preceding constituent. In (8) we offer a representation of the English

word pity. This results in a larger ‘foot’ structure in which the onset to the second syllable is

underneath the first syllable. Such a configuration encodes a generalization sometimes

referred to as ‘ambisyllabicity’ (Kahn 1976), by which the second syllable ‘captures’ the coda

of the first, which is in a prosodically weak position. As a result, the second consonant in a

trochaic CVCV foot is subject to lenition (see Jensen, 2000; Harris, 2004). The /t/ in this word

is realized as a tap or a glottal stop in various vernacular dialects of English. A segmentally

‘similar’ word in Polish, PIT-y ‘tax returns’, would not contain submerged structure. The two

23

constituents would be adjoined at a higher level of structure, and the /t/ is not subject to

lenition processes. The larger foot structure in (8) may also find parallels in the relative

prominence of stressed and unstressed vowels in the two languages. English, of course, is

characterized by significant vowel reduction, while in Polish vowel reduction is less dramatic.

(8) English pity

In sum, our discussion points to an opposition between English and Polish with regard to

relations between individual segmental structures and the primitive CV tree in (1). English

offers the possibility of submersion, associated with long vowels, weak coda consonants, and

weak consonants in VCV contexts. Submersion is absent in Polish. Codas and intervocalic

consonants are generally not subject to weakening, and vowel quantity distinctions are absent.

The submersion parameter also has implications for boundary formation. Submersion of

initial vowels in English has prosodic motivation originating in the lack of VO specification.

The less prominent status of English initial vowels leads weakening processes by which

prosodic constituents do not always respect the boundaries imposed by individual lexical

items. By contrast, in Polish, VO specification and promotion serve to ensure that for the most

part, the terms ‘initial’ and ‘final’ as defined by lexical entries receive a more rigid

interpretation in relation to the phonological shape of words.

A crucial feature of the Onset Prominence model is that segmental representations and

prosodic constituents are constructed of the same structural materials, rather than being joined

by association lines. This perspective provides insight on the relationship between segments

and syllables, which has long been a source of debate in phonological theory (cf. cue vs.

prosodic licensing; e.g. Steriade, 1997), and persistent riddles in the study of L2 phonological

acquisition. In what follows, we apply the OP perspective to one such riddle: perceptual

epenthesis by Korean learners of English (de Jong & Park, 2012).

5.2 Reconciling models of L2 vowel epenthesis

The phenomenon of vowel epenthesis is extremely common among L2 learners, both in

production and perception. The apparent motivation for this process is to repair structures that

are phonotactically illicit in the L1. These may include clusters of consonants, as well as

consonants in coda position. Korean learners of English have received much attention in this

regard. Particularly puzzling is that fact that Korean speakers often epenthesize, both in

production and perception, after L2 coda stops, even though their L1 allows stops in coda

position. De Jong & Park (2012) studied perceptual epenthesis by Korean learners of English.

Their stated goal was to test the predictions of two explanations for epenthesis. According to

24

the first, which attributes epenthesis to ‘functional reparsing’, the process is motivated by the

need to license consonant manner and laryngeal contrasts in a new prosodic position.6 That is,

it serves to ease the task of identifying the consonant in question. In the other model, under

the heading of ‘perceptual misanalysis’, epenthesis is the reinterpretation of consonant release

as the ‘onset’ to an additional syllable, whose ‘nucleus’ is filled by an epenthetic vowel. De

Jong and Park note that authors who have argued for these models often claim that segment-

based and syllable-based explanations for epenthesis are incompatible. To test the two models De Jong & Park (2012) carried out a perceptual experiment in

which L1 Korean listeners engaged in two tasks with stimuli from American English: a

syllable counting task and a segment identification task. Their predictions with regard to the

aforementioned models were as follows. A negative relationship between segment

identification and syllable counting would provide support for the contrast-based model. That

is, more accurate segment identification comes at the cost of less accurate prosodic parsing,

since the additional syllable is claimed to aid in identification of the newly reparsed

consonant. No correlation between the two tasks would support the syllable-based model.

Finally, they posit that a positive relationship between the two tasks would support an

alternative model in which segmental identification and prosodic parsing are two aspects of

the same perceptual process. Their findings showed a positive correlation between syllable

counting and segmental features across individual subjects. Learners who were more accurate

in the syllable counting task (i.e. less likely to hear epenthetic vowels) tended to be more

accurate in identifying segmental features. Thus, it appears that neither of the two tested

models was supported. Rather, as they point out, ‘the present results suggest an overall model

. . . wherein listeners jointly interpret the details of segments and the syllabic position from an

integrated percept (De Jong & Park, 2012: 150)’.

The integrated percept proposed by De Jong & Park may be captured in the Onset

Prominence representational environment, in which segmental and syllabic structures are

constructed from the same hierarchy. Crucially, manner of articulation is a prosodic

specification rather than a segmental feature. Instead of a segmental specification attaching to

prosodic structure by means of association lines, manner is prosodic structure. Thus, any

percept of manner is inevitably integrated with prosody, as De Jong & Park propose. It is also

worth noting that manner accuracy showed the most robust correlation with syllable counting

accuracy in De Jong & Park’s experiment (2012: 145, Figure 4).

5.2.1 Coda adaptation and Korean phonotactic constraints

Epenthesis in the adaptation of English codas into Korean has been classified as a case of

‘unnecessary repair’ (Kang 2011), since L1 Korean does allow coda stops. However, Korean

codas are restricted in two important ways. First, the suppression of stop release is obligatory.

In addition, manner and laryngeal contrasts are neutralized. To provide some perspective on Korean phonotactic constraints, OP representations

for the three Korean labial stops are proposed in (9). Crucially, the framework allows for the

possibility that different melodic specifications may be housed at different levels of the OP

hierarchy in accordance with their phonetic realization. Place is specified as a [labial]

annotation on the Closure node. This is to be expected since it is the location of the closure

that defines stop place of articulation. By contrast, laryngeal features, whose phonetic

realization may be impeded by stop closure, may be assigned at lower levels. This is shown in

(9). Aspiration, which is of course associated with aperiodic noise, is shown as a [spread

glottis] specification on the Noise node. Tenseness is represented as a [constricted glottis]

6 Since Korean features unreleased stops in which place is encoded in coda positions, it might be expected that

Korean listeners should be quite accurate at identifying the place of articulation of coda consonants.

25

([cg]) annotation on the VO node. This feature is associated with a stiffer voice quality on the

onset of the following vowel (e.g. Ladefoged & Maddieson 1996), so the VO node is a natural

structural position for [cg] specifications. With these representations in mind, we may turn to

the representation of codas in Korean, which are characterized by the presence of place

contrasts, but neutralized manner and laryngeal contrasts.

(9) Proposed representations of Korean /p/, /pʰ/, and /p*/

In the OP environment, Korean codas may be attributed to submersion, producing the

structure in (10).

(10) Korean CVC sequence

To explain the fact that Korean maintains place contrasts in coda stops, but neutralizes

laryngeal constrasts, we need only propose a constraint against multiple layers of submerged

structure. That is, Korean, like many other languages, appears to restrict the size of syllable

rimes. The claim would be that Korean only allows a single node under the VT level. The

laryngeal specification, which as we saw in (10) are housed on lower-level nodes, loses its

structural housing and is not realized in this position. This is shown in (10) as the crossed-out

labels of the lower Noise and VO nodes. Thus, the apparent mismatch in Korean between a

licensed place contrast and neutralized laryngeal contrast may be explained as a single

constraint on the size of prosodic constituents.7 With the submerged Noise and VO nodes

eliminated in (10), it also falls out naturally that coda stops in Korean are always produced

without an audible release. The only remaining part of the stop is Closure; the lower nodes

associated with stop release have been eliminated.

Kang (2003) provides evidence that the presence of epenthesis in English loanwords in

Korean is closely related to the probability that the English coda stops are produced with an

audible release. Epenthesis is expected when the target language coda is more likely to

contain a release burst, which in Korean only occurs in syllable onsets. Thus, released stops

are adapted with an additional prosodic constituent whose prominence is enhanced by the

7 This restriction may capture the fact that coda fricatives are also realized as unreleased stops. Space restrictions

prevent us from explaining this in detail.

26

epenthetic vowel. Polish requires stop release in codas.8 In these cases we would claim that

these stops are not submerged under the preceding rhyme. Rather, they remain at their

underlying level of the OP hierarchy. Moreover, epenthesis after coda is standard in the

speech of Korean learners of Polish (Dziubalska-Kołaczyk, p.c.). It is not subject to the same

variability found in Korean English. Kang attributes the link between epenthesis in Korean English and target language

stop release to ‘perceptual similarity’, arguing for the importance of a non-contrastive

phonetic detail, stop release, in the mechanism of loanword adaptation. From the OP

perspective, stop release, though non-contrastive, is not merely a phonetic detail. It is

predictable on the basis of phonological parameters and constraints. The lack of release is

surely a systemic element of Korean phonology; it should be representable in phonological

terms. The OP environment offers phonological tools for the representation of such non-

contrastive phenomena. At the same time, OP representations allow for a unified description

of a range diverse phonological patterns. For example, the claim that submersion is absent

from Polish accounts for the following aspects of Polish phonology: the obligatory release of

coda stops, the lack of vowel length distinctions, the lack of lenition in VCV contexts, and the

tendency for glottalized realization of initial vowels.

6 Final remarks

This paper has presented acoustic and perceptual data on the realization of word-boundary

vowel hiatus in the speech of Polish learners of English. Since the theoretical perspective

from which our research hypotheses were formed lies outside the mainstream viewpoint of

most researchers in generative and applied linguistics, we shall conclude by offering some

clarification of the assumptions underlying our study.

The integration of segmental and prosodic structures in the OP environment is inspired

by the view of phonetic implementation espoused by Natural Phonology (e.g. Donegan and

Stampe 1979). In NP, phonological representations interact directly with speech, without an

intervening level of categorical phonetics. That is, ‘the feature and prosodic specifications of

the phonological representation are interpreted through the action of speaking, in an automatic

but highly contextually-determined way’ (Donegan, 2002: 58). This interpretation is

envisioned in terms of the application and suppression of phonetically-motivated

phonological processes. OP representations facilitate the explicit implementation of this idea,

allowing for more nuanced descriptions of phonetically-motivated phonological behavior than

those afforded by the standard principles of articulatory ease and perceptual clarity. Crucially,

instead of being thought of in linear segmental terms (Øʔ, Ø j, ʔ Ø, etc.), natural

processes are envisioned as adjustments to a hierarchical representation.

This is evident in the present study of vowel hiatus and hiatus resolution, which

suggests that learner success may be facilitated not only through the acquisition of L2

processes, but also through the suppression of L1 processes. Process application and

suppression are closely linked in the NP approach. At the same time, OP structures offer a

new and insightful view on the representational motivation and consequences of NP

processes. For example, vowel glottalization has clear motivation as a listener-friendly

fortition, yet beyond this characterization it has two different interpretations. In languages like

Polish, it preserves or strengthens a segmental structure that defines a prosodic boundary. By

contrast, in languages like English glottalization, when it occurs, adds to the structure of an

initial vowel to introduce a boundary. What is referred to as ‘glide insertion’ is subject to a

8 In current work, we are examining the acquisition of English unreleased stops by Polish learners of English.

27

different interpretation. It appears to be a perceptual process that is not reflected consistently

in production. In this sense it is similar to other perceptual processes in NP (Donegan and

Stampe, 1979), such as the perceptual denasalization process that occurs when English

speaking listeners hear the nasalized vowel in went [w nt] as an oral vowel. In production,

the modal hiatus that induces the glide percept is a speaker-friendly process insofar as it does

not require additional glottal constriction on the V#V sequence. At the same time, however,

the modal realization reflects submersion, a prosodically motivated process with deeper

implications for English phonology. Our study applies a new perspective on NP process application to the field of L2 speech

acquisition. We are not aware of other SLA research linking the glottalization of vowels or its

suppression to other aspects of segmental phonology. The main innovation in our approach

lies in abandoning the assumption that glottalization and modal hiatus/glide insertion are

separate processes. Rather we suggest that the various realizations of vowel hiatus reflect

different aspects of process application within a single representational hierarchy.

References

Babel, M. (2012). Evidence for phonetic and social selectivity in spontaneous phonetic

imitation. Journal of Phonetics 40: 177-189.

Best, C. T. (1995). A direct realist perspective on cross-language speech perception. In W.

Strange (Ed.), Speech perception and linguistic experience: Issues in cross-language research (pp. 171-204). Timonium, MD: York Press.

Best, C. T., & Tyler, M. D. (2007). Nonnative and second-language speech perception:

Commonalities and complementarities. In M. J. Munro & O.-S. Bohn (Eds), Second

language speech learning – the role of language experience in speech perception and

production (pp. 13-34). Amsterdam: John Benjamins.

Boersma, P. & Weenink, D. (2011). Praat: doing phonetics by computer. [Computer

program].Version 5.2.18.

Britain, D. & S. Fox. (2008). Vernacular universals and the regularisation of hiatus resolution.

Essex Research Reports in Linguistics, 57, 1-42. Bybee, J. (2001). Phonology and Language Use. Cambridge: Cambridge University Press.

Cebrian, J. (2000). Transferability and productivity of L1 rules in Catalan-English

interlanguage. Studies in Second Language Acquisition, 22, 1-26. Chang, C. 2012. Rapid and multifaceted effects of second language learning on first language

speech production. Journal of Phonetics 40, 249-268.

Cook, A. 1991. American Accent Training. Hauppauge, NY: Barron’s Educational Series, Inc. Cooke, M., J. Barker, M. Lecumberri (2013). Crowdsourcing in Speech Perception, In M.

Eskenazi, G. Levow, H. Meng, G. Parent and D. Sundermann (Eds.), Crowdsourcing

for Speech Processing. 137-172. Hoboken, NJ: John Wiley and Sons.

Crosswhite, K. (2003). Spectral tilt as a cue to word stress in Macedonian, Polish, and

Bulgarian. In Sole, M.J., D. Recasens & J. Romero (eds.). Proceedings of XVth

International Congress of Phonetic Sciences, Barcelona, 767-770. Cruttenden, A. 2001. Gimson’s Pronunciation of English (6

th ed.). London: Arnold.

Crystal, T. & A.S. House. (1988). The duration of American English stop consonants: an

overview. Journal of Phonetics, 16, 285-294.

Davidson, L. and D. Erker. (To appear). Hiatus resolution in American English: the case

against glide insertion. Language.

28

Derwing, T. M., & Munro, M. J. (1997). Accent, intelligibility, and comprehensibility:

Evidence from four L1s. Studies in Second Language Acquisition, 19, 1-16.

Dogil, G. (1999). The phonetic manifestation of word stress in Polish, Lithuanian, Spanish,

and German. In H. van der Hulst (ed.), Word Prosodic Systems in the Languages of

Europe (pp. 273-311). New York: Mouton de Gruyter. Donegan, P. (2002). Phonological processes and phonetic rules. In: Future Challenges for

Natural Linguistics, ed. Katarzyna Dziubalska-Kołacyk and Jarosław Weckworth, pp.

57-81. (LINCOM Studies in Theoretical Linguistics 30.) Muenchen: LINCOM

EUROPA

Donegan, P. and D. Stampe. (1979). The study of natural phonology. In: Current Approaches

to Phonological Theory (Conference on the Differentiation of Current Phonological

Theories, Bloomington, Sept. 30-Oct. 1, 1977), ed. Daniel A. Dinnsen, pp. 126-173.

Bloomington: Indiana University Press

Downing, Laura. 1998. On the prosodic misalignment of onsetless syllables. Natural

Language & Linguistic Theory, 16, 1-52.

De Jong, K. & H. Park. (2012). Vowel epenthesis and segmental identity in Korean learners

of English. Studies in Second Language Acquisition, 34, 127-155. Dilley, L., S. Shattuck-Hufnagel & M. Ostendorf. (1996). Glottalization of word-initial

vowels as a function of prosodic structure. Journal of Phonetics, 24, 423-444.

Dukiewicz, L. & I. Sawicka. (1995). Gramatyka współczesnego języka polskiego – fonetyka i fonologia [Grammar of modern Polish – phonetics and phonology]. Krakow:

Wydawnictwo Instytutu Języka Polskiego PAN. Escudero, P. & Boersma, P. (2004). Bridging the gap between L2 speech perception research

and phonological theory. Studies in Second Language Acquisition, 26, 551-585.

Flege, J. and W. Eefting (1987). Cross language switching in stop consonant perception and

production by Dutch learners of English. Speech Communication 6, 185-202. Goldinger, S. (1997). Perception and production in an episodic lexicon. In Johnson, K.

Mullennix, J. W. (eds.). Talker Variability in Speech Processing (pp. 33-66). San

Diego: Academic Press. Goldinger, S. (1998). Echoes of echoes? An episodic theory of lexical access. Psychological

Review, 105 (2), 251-279.

Gussmann, E. (2007). The phonology of Polish. Oxford: Oxford University Press. Hansen Edwards, J. & M. Zampini. Phonology and Second Language Acquisition.

Amsterdam: John Benjamins. Harris, J. (2004). Release the captive coda: the foot as a domain of phonetic interpretation. In

J. Local, R. Ogden & R. Temple (eds.), Phonetic interpretation: Papers in Laboratory

Phonology 6, 103-129. Cambridge: Cambridge University Press.

Hewings, M. and S. Goldstein. 1999. Pronunciation plus: Practice through interaction.

Cambridge: Cambridge University Press. Hillenbrand, J. and R. Houde. 1996. The role of F0 and amplitude in the perception of

intervocalic glottal stops. Journal of Speech and Hearing Research 39. 1182–1190

Honorof, D. N., Weihing, J., Fowler, C. A. (2011). Articulatory events are imitated under

rapid shadowing. Journal of Phonetics 39: 18-38. Howard, M. (2008). 'On the role of naturalistic and classroom exposure in the acquisition of

socio-phonological variation: A longitudinal study of French liaison'. Journal of

Applied Linguistics, 5 (2), 159-179. van der Hulst, H. 2010. A note on recursion in phonology. In H. van der Hulst, (ed.).

Recursion and Human Language, 301-342. Berlin: Mouton de Gruyter.

Jensen, J. (2000). Against ambisyllabicity. Phonology 17: 187-235.

29

Johnson, K. (1997). Speech perception without speaker normalization: an exemplar model. In

K. Johnson & J. Mullennix, (Eds.). Talker variability in speech processing (pp. 145-

166). San Diego: Academic Press. Kahn, D. (1976). Syllable-based generalizations in English phonology. PhD dissertation,

Massachusetts Institute of Technology.

Kang, Y. (2003) Perceptual similarity in loanword adaptation: English post-vocalic word-final

stops to Korean. Phonology 20 (2): 219-273.

Kang, Y. (2011) Loanword phonology. In van Oostendorp, Marc, Colin Ewen, Elizabeth

Hume, and Keren Rice, eds., Companion to Phonology. Wiley-Blackwell.

Ladefoged, P. and I. Maddieson. (1996). The Sounds of the World’s Languages. Oxford:

Blackwell.

Lecumberri, M. and J. Maidment (2000). English transcription course. Oxford: Routledge.

Levi, S. (2008). Phonemic vs. derived glides. Lingua, 118,1956-1978.

Lindblom, B. (1990). Explaining phonetic variation: a sketch of the H&H theory. In Speech

Production and Speech Modelling, edited by W. J. Hardcastle and A. Marchal (The

Netherlands: Kluwer Academic), pp. 403-439.

LLeo, C. & I. Vogel. (2004). Learning new segments and reducing domains in German L2 phonology: The role of the Prosodic Hierarchy. International Journal of

Bilingualism, 8, 79-104. Lujan, A.B. 2006. The American Accent Guide (2

nd ed.). Salt Lake City: Lingual Arts.

McCarthy, J. 1993. A case of surface constraint violation. Canadian Journal of Linguistics,

38.169-95.

Malisz, Z, M. Żygis & B. Pompino-Marschall. (2013). Rhythmic structure effects on

glottalisation: a study of different speech styles in Polish and German. Laboratory

Phonology, 4, 119-158. Marlett, S. & J. Stemberger. (1983). Empty consonants in Seri. Linguistic Inquiry, 14, 617-

639.

Munro, M. J. (2008). Foreign accent and speech intelligibility. In Hansen Edwards, J. G. &

Zampini, M. L. (Eds.). Phonology and Second Language Acquisition (pp. 193-218).

Amsterdam: John Benjamins.

Newlin-Łukowicz, L. (2012). Polish Stress: looking for phonetic evidence of a bidirectional

system. Phonology, 29(2), 271-329.

Pardo, J. S., Gibbons, R., Suppes, A. & Krauss, R. M. (2012). Phonetic convergence in

college roommates. Journal of Phonetics, 40, 190-197. Pierrehumbert, J. (2001) Exemplar dynamics: Word frequency, lenition, and contrast. In J.

Bybee and P. Hopper (eds.) Frequency effects and the emergence of lexical structure.

John Benjamins, Amsterdam. 137-157.

Plag, I., G. Kunter, & M. Schramm. (2011). Acoustic correlates of primary and secondary

stress in North American English. Journal of Phonetics,39, 362-374.

Prince, A. & P. Smolensky. 1993. Optimality Theory: Constraint interaction in a generative grammar. Rutgers University Optimality Archive.

Redi, L. & S. Shattuck-Hufnagel. (2001). Variation in the realization of glottalization in

normal speakers. Journal of Phonetics, 29, 407-429. Roach, P. 2009. English Phonetics and Phonology. Cambridge: Cambridge University Press

Rojczyk, A. (2012). Phonetic and phonological mode in second-language speech. VOT

imitation. Paper presented at EUROSLA 2012, Poznań, Poland, September 5-8 2012. Rojczyk, A. (2013). Phonetic imitation of L2 vowels in a rapid shadowing task. In Lewis, J &

LeVelle, K. (eds). Proceedings of the 4th Pronunciation in Second Language Learning

and Teaching Conference (pp. 66-76). Ames, IA: Iowa State University.

30

Rojczyk, A., Porzuczek, A. & Bergier, M. (2013). Immediate and distracted imitation in

second-language speech: Unreleased plosives in English. Research in Language, 11, 3-

18. Rubach, J. (2000). Glides and glottal stop insertion in Slavic languages – a DOT accoutn.

Linguistic Inquiry, 31 (2), 271-317. Schwartz, G. (2013a). Vowel hiatus at Polish word boundaries – phonetic realization and

phonological implications. Poznań Studies in Contemporary Linguistics, 49 (4), 557-

585. Schwartz, G. (2013b). A representational parameter for onsetless syllables. Journal of

Linguistics, 49 (3), 613-646. DOI: http://dx.doi.org/10.1017/S0022226712000436. Schwartz, G., A. Balas & A. Rojczyk. (to appear). External sandhi in L2 segmental phonetics

– final (de)voicing in Polish English. In Proceedings of New Sounds 2013.

Shockley, K., Sabadini, L. & Fowler, C. A. (2004). Imitation in shadowing words. Perception

and Psychophysics, 66, 422-429. Shoemaker, E. (2010). Nativelike Attainment in L2 Listening: The segmentation of spoken

French. In Dziubalska-Kołaczyk, K., M. Wrember & M. Kul (eds.) Proceedings of the

6th international symposium on second language speech, New Sounds 2010, Poznań,

Sluijter, Agaath M.C. & Vincent J. van Heuven. 1996. Spectral balance as an acoustic

correlate of linguistic stress. Journal of the Acoustical Society of America, 100, 2471-

2485.

Steriade, D. 1997. Phonetics in phonology – the case of laryngeal neutralization. Ms. UCLA.

Sturm, J. (2013). Liaison in L2 French: The effects of instruction. In. J. Levis & K. LeVelle

(Eds.). Proceedings of the 4th

Pronunciation in Second Language Learning and

Teaching Conference, Aug. 2013 (pp. 157-166). Ames, IA: Iowa State University.

Uffmann, C. 2007. Intrusive [r] and optimal epenthetic consonants. Language Sciences,

29.451-76.

Wells, J.C. Longman Pronunciation Dictionary (3rd

ed.). Harlow: Pearson Education Limited.

Wiese, R. (2000). The phonology of German. Oxford: Clarendon Press. Wright, R. (2004). Perceptual cue robustness and phonotactic constraints. In Hayes, B., R.

Kirchner and D. Steriade (eds). Phonetically Based Phonology. Cambridge: Cambridge University Press, 34-57.

Yuasa, I. (2010). Creaky voice: a new feminine voice quality for young urban-oriented

upwardly mobile American women? American Speech, 85, 315-37. Zsiga, E. (2003). Relearning consonant timing. Studies in Second Language Acquisition, 25,

399-432. Zsiga, E. (2011). External sandhi in a second language: The phonetics and phonology of

obstruent nasalization in Korean and Korean-accented English. Language 87. 289 - 345.

31

Appendix 1 – stimuli for production experiment

1-stay out 2-try out

3-see all 4-way out 5-go out 6-know everything 7-saw everything

8-play it 9-know Alex 10-how interesting

11-know after 12-grow excellent 13-try each 14-they always

15-go every day 16-they actually 17-car always 18-your idea

19-the other 20-the end 21-they asked

22-be afraid

23-tell me all 24-I often 25-sure I

26-holiday activities

32

Appendix 2 – Tables for binary regression analyses in production experiment

Reading task - %Modal

B SE Wald df Sig. Exp(B)

sex -,305 ,211 2,102 1 ,147 ,737

advanced ,440 ,183 5,791 1 ,016 1,553

TFreq ,441 ,106 17,375 1 ,000 1,554

Constant -,750 ,233 10,367 1 ,001 ,472

Reading task - %Glottal Stop

B SE Wald df Sig. Exp(B)

sex 1,059 ,489 4,691 1 ,030 2,884

advanced -1,128 ,355 10,099 1 ,001 ,324

TFreq -,653 ,194 11,388 1 ,001 ,520

Constant -2,238 ,489 20,976 1 ,000 ,107

Imitation task %Modal

B SE Wald df Sig Exp(B)

sex -,128 ,245 ,273 1 ,601 ,880

advanced ,489 ,209 5,445 1 ,020 1,630

TFreq ,675 ,126 28,530 1 ,000 1,964

Constant ,369 ,256 2,082 1 ,149 1,447

Imitation - %Glottal Stops

B SE Wald df Sig. Exp(B)

TFreq -,653 ,194 11,388 1 ,001 ,520

sex 1,059 ,489 4,691 1 ,030 2,884

advanced -1,128 ,355 10,099 1 ,001 ,324

Constant -2,238 ,489 20,976 1 ,000 ,107

33

Across tasks - %Modal

B SE Wald df Sig. Exp(B)

sex -,231 ,161 2,059 1 ,151 ,794

advanced ,462 ,138 11,219 1 ,001 1,587

Task 1,462 ,135 116,482 1 ,000 4,316

TFreq ,539 ,081 44,873 1 ,000 1,715

Constant -,909 ,188 23,452 1 ,000 ,403

34

Appendix 3 – Stimuli for listening tests, with additional segmental errors

Utterance Errors in glottal token Errors in modal token

and they asked me – –

I go every day – –

his car always breaks

down – short VOT in /k/,

devoiced /z/ in his

and always

I’ll know after the exam vowel quality in

know –

I’m sure I heard a

telephone ringing – ng in ringing

I often imagine things vowel quality, ng –

I saw everything – –

see all the pictures unaspirated /p/ vowel quality in all

why did you stay out all

night – –

they actually like quality of /æ/ in

actually

–

they always have

something prepared

– –

we’ll be unable to send – –