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International Journal of English Linguistics; Vol. 8, No. 5; 2018 ISSN 1923-869X E-ISSN 1923-8703
Published by Canadian Center of Science and Education
27
Acoustic Characteristics of Pakistani English Vowel Sounds
Abdul M. Abbasi1, Mansoor A. Channa2, Masood A. Memon3, Stephen John4, Irtaza Ahmed5 & Kamlesh5 1 Department of Allied Subjects, Sindh Madressatul Islam University, Karachi, Pakistan 2 Department of Basic Sciences, Quaid-e-Awam University, Nawab Shah Sindh, Pakistan 3 Department of English, Cadet College Petaro, Hyderabad, Sindh, Pakistan 4 Department of Education, Sindh Madressatul Islam University, Karachi, Pakistan 5 Department of Computer Sciences, Sindh Madressatul Islam University, Karachi, Pakistan
Correspondence: Abdul M. Abbasi, Department of Allied Subjects, Sindh Madressatul Islam University, Karachi, Pakistan. E-mail: [email protected]
Received: December 28, 2017 Accepted: January 26, 2018 Online Published: May 5, 2018
doi:10.5539/ijel.v8n5p27 URL: https://doi.org/10.5539/ijel.v8n5p27
Abstract The purpose of this investigation was to document acoustic characteristics of Pakistani English (PaKE) vowel sounds. The experiment was designed to examine the properties of ten vowels produced by Pakistani ESL learners. The analysis is based on the voice samples of recorded 50 CVC words. Total 5000 (10× 10 × 50=5000) voiced samples were analyzed. The data consisted of 50 words of ten English vowel sounds [i: ɪ e ɔ: æ ə ɑ: u: ɒ ʊ]. Ten ESL speakers recorded their voice samples on Praat speech processing tool installed on laptop. Three parameters were considered i.e., fundamental frequency (F0), vowel quality (F1-F2) and duration. Formant patterns were judged manually by visual inspection on Praat Speech Processing Tool. Analysis of formant frequency shows numerous differences between male and female of F1 and F2, fundamental frequency and duration of English vowels. The voice samples provide evidence for higher and lower frequency of vowel sounds. Additionally, the data analysis illustrates that there were statistical differences in the values of short and long vowels coupled with vowel space plot showing explicit differences in locating the production of vowels of male & female vowel space acoustic realizations.
Keywords: acoustic characteristics, vowel sounds, frequencies, Pakistani ESL
1. Introduction This study is based on 5000 voice samples (10× 10 × 50=5000) which were analyzed in a very careful manner. The experiment was designed to document English vowel properties produced by Pakistani English speakers. To analyze PaKE vowels, three phonetic exponents were considered as parameters for the analysis e.g., duration, fundamental frequency and first and second formant frequency. The study focuses on the characterization of vowel sounds produced by English as Second Language (ESL) learners and the positions of Pakistani vowels space in vowel space plot of mouth cavity. The objectives behind this study are to document the variations in frequencies of 10 different English vowels by ESL learners. Every vowel has different frequency and the vowel space plot when it is pronounced by different people it contains a different frequency, plot, and duration coupled with different pitch. Praat speech processing tool was utilized to analyze the sounds with the help of spectrographic view. Praat calculated the average of all 5000 sounds. The measurements were categorized in terms of male, female and third their measurements were compared with each other. The study tests the hypothesis that if ESL learners pronounce English vowels, then their placement of vowels on vowel space will be differently placed by male and female Pakistani ESL learners. Based on the research questions as follows: What are the acoustic realizations of PaKE English vowel sounds? What is difference in placement of acoustic vowel space plot between male and female?
Additionally, the study focuses on acoustic properties of English vowel sounds and their acoustic vowel space in vowel inventory plot. The vowels are basically categorized referencing three phonetic factors i.e., height of the vowel, back-ness and lip rounding. Olive, Greenwood, & Coleman (1993) contends “An acoustic analysis of vowels stresses the different formant configurations that are characteristic of each vowel. The relationship among the vowels can be examined by comparing their formant values”. Front-back and high-low differences are
ijel.ccsenet.org International Journal of English Linguistics Vol. 8, No. 5; 2018
28
characterized by the second and the first formants, illustrating on spectrographic images. If the formant value is high, the closer the vowel becomes to the front point. In so far as front vowel is concerned frequency F1 turns out to be lower and contraction escalates in the vocal track. F1 and F2 frequencies are regarded as a vowel quality in acoustic speech terms. Generally unstressed vowels are reduced in quality; whereas the stressed vowels have higher frequencies. There are several features in the production of sounds, i.e., reduction of vowel quality, vowel lengthening followed by the voiced sound. Another important factor is absence and presence of lexical stress which affects the vowel quality. The unstressed syllables in American English are reduced in quality therefore, they involve in vowel centralization to schwa vowel sound, the chiefly produced sound in English language. F1 and F2 formants have greater distance when there occurs in between the highest vocal sounds. Whereas, for back vowel, F2 is much closer and lower to F1 for the back vowels than for the front vowels (Parson, 1987).
2. Methods 2.1 Procedures of Data Collection
The data was collected from 10 subjects (5 male and 5 female). Their age ranged from 17 to 22 years. The recordings were made in a silent zone where there was no background noise. ESL learners were given 50 indexing cards written on them the token phrase in between the token words, all ten vowels were placed as illustrating Table 1. Ten vowels were selected as follows: /i:, ɑ:, ɪ, ɔ:, æ, ə, u:, ɒ, e, ʊ/. Then five words from each vowel sound and then written them on the cards. Then we have given those cards to our respected subjects and then well requested them to pronounce each word three times. Each subject pronounces the 50 words three times like I say token word.
2.2 Speech Material
Five words from each vowel sound were chosen for the experiment. Total chosen words were mono-syllable words. The words frequency in daily use was highly familiar to ESL learners. Table 1 illustrates the fifty mono-syllable words which were used as the data tool as follows:
Table 1. Token words produced by ESL learners
Vowels Words Words Words Words Words
i: Peep Sheep Meet Seat Neat e Pet Set Get Wet Net ɑ: Car Far Jar Part Half ɔ: Core Four Snore Score Saw ɒ Pot Cot Short Lot Sort ɪ Fit Bit Sit Pit Kit æ Fat Back Bad Cat Sat u: Boot Food Soon Moon Tooth ə Dug But Bus Cut Bud ʊ Should Could Good Put Food
2.3 Recordings
Recordings were made of /hVd/ utterances recorded by ten male and female speakers. Measurements were analyzed of vowel duration, F0 contours (fundamental frequency), and formant frequency contours (F1-F2). A set of 50 cards with each word written on them was provided among the participating subjects. Total fifty words (25 for short & 25 for long vowels) were involved. The word structure was selected where each vowel sound was amid the word. There was a total of 50 cards, i.e., one card for each word inscribing “I say token word now” in a phrase. In addition, the set of 50 cards was read with 03 repetitions by each ESL learners. The cards were reshuffled after each recording, and the subjects read aloud the word on each card in sequence with no break between repetitions. In addition, the participants were provided a quiet and calm environment, with no background noise, in a closed room far from the noise of city traffic. The voice recorder used faced them at a distance of around six inches. They were instructed to maintain a normal speech rate and to read the given words using a neutral focus, as in ordinary talking conditions. Subjects voiced were recorded on sound recorder and analyzed on computer Dell Core 2 dual system using the Praat speech processing tool (Boersma & Weenink, 2017) and a voice recorder.
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2.4 Data A
The recorparameterstaken as mwere on puthe data fcarefully. duration acalculated belongs togot the plo
3. Discuss3.1 Measu
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29
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Vol. 8, No. 5;
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Vol. 8, No. 5;
presents the F1lue (727 Hz) oel i: has the hig
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time duration oe subjects. Fro
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Vol. 8, No. 5;
Sig. (2-tailed)
036
006
The vocalic anasent study analof short vowels
by female suburation. Statistimale speakers. rs.
represents the e subjects havmong the 10 ve subjects have
rt vowel has ave found thaue as comparrence betweenand the unstreel (2008) hasana, Kakepotoof English sylners.
2018
alysis lyzed s was bjects ically Male
male e the
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high at the ed to n the essed
also o, Ali, lable
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4. Results4.1 Overal
The result research asof the maleof the femaverage F0the male sppitch and dshows thatthe smallevalue (190male and f
English voillustrated correspondfrequency within the
Female proand in heivowel spacʊ/ are locathe back.
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s ll F1 and F2 of
shown that thspects (F1, F2e speaker has t
male speakers 0 of female supeakers have tduration were t the vowel ɑ:
est value (463.02 HZ) of F2 ofemale subject
Fig
owel space ploin Figure 6.
ds to the gapof F1. Basicalmouth cavity.
oduction of Enight 450 Hz; wce with the heiated between F
In
of Subjects
he vowel sound, F0 and duratithe highest valhas the highe
ubjects has the the high value analyzed by Phas the highes6 HZ) of F1 oof male and fes from 10 vow
gure 5. English
ot illustrates t. The acoustic
p between F1 lly, it involves
Fig
nglish vowels whereas other ight of F1 500
F2 1200-1450 H
nternational Jou
d produced by ion). The statislue as compare
est value as cogreater value of duration as
Praat the speecst value (712.5of male and feemale subjectswels.
h ten vowels d
ten vowels locc vowel spacformant and
tongue body p
gure 6. Female
are as followsfront vowels
0-600 Hz in betHz horizontall
urnal of English
32
ESL speakers stics which areed to female spompared to mas compared t
s compared to fch processing t HZ) of F1 of
emale subjects while ɔ: (128
duration by acr
cation within tce is based o
F2 formant wposition repres
e English vowe
s: Front vowel i.e., /ɪ, e, æ/
tween in moutly and F1 whil
Linguistics
both male ande shown in thepeaker. The sta
male speakers. to male speakefemale speaketool. From thismales and femfrom 10 vow
80.5 HZ) vowe
ross female ES
the vowel spaon first two fwhereas the vsenting high v
el space plot
/i: / is locatedare positioned
th cavity. Centle lower centra
d female has de graph shows atistics shows The statistics
ers. The statister. The formants graphical rep
male subjects aels. The vowe
el has the smal
SL speakers
ace produced bformants; whevertical axis cs low and fron
d between 1800d between 170tral and back val vowel ɑ: dec
Vol. 8, No. 5;
different valuesthat the averagthat the averagillustrates tha
tics also showst frequency (Fpresentation, wand the vowel iel i: has the higllest value of F
by ESL learneere horizontal corresponds tont vs back loca
0-1900 Hz F2 00-1800 Hz onvowels /u:, ɒ, ɔcentralized tow
2018
s of 4 ge F1 ge F2 at the s that 1, F2)
which i: has ghest F2 of
ers as axis
o the ations
axis, n the : and
wards
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5. ConclusThe study variety spoview of sparametersmale subjesubject ha(170 Hz) acompared PaKE prodspace acou
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Appendix A Vowels i: e ɑ: ɔ: ɒ 1 Peep Pet Car Core Pot 2 Sheep Set Far Four Cot 3 Meet Get Jar Snore Short 4 Seat Wet Part Score Lot 5 Neat Net Half Saw Sort
Vowels ɪ æ u: ə ʊ 6 Fit Fat Boot Dug Should 7 Bit Back Food But Could 8 Sit Bad Soon Bus Good 9 Pit Cat Moon Cut Put 10 Kit Sat Tooth Bud Food
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