Hoarse meeting in Liverpool April 22, 2005

Subglottal pressure and NAQ variation in Classically Trained Baritone Singers

Eva Björkner*†, Johan Sundberg†, Paavo Alku *Laboratory of Acoustics and Audio Signal Processing, Helsinki University of Technology, Finland

†Department of Speech Music Hearing, KTH, Stockholm, Sweden

Air => Subglottal pressure

(Ps)

Oscillation =>pulsating air flow => voice source

Sound => vowels and consonants

Voice production

TEAC Multi channel digital recorder

Flow (Rothenberg mask)

Audio

Oral pressure

Inverse Filtering

DeCap – Svante Granqvist

Flow glottogram Flow glottogram parametersparameters (Time-based & amplitude-based)

Time [s]

0,002 0,004 0,006 0,008 0,01 0,012

0,002 0,004 0,006 0,008 0,01 0,012

Time [s]

Time [T0]

Derivative [MFDR]

Ûp-t-p

Peak-to-peak pulse amplitude

Flo

w

Deri

vati

ve

Flow

Negative peak of the differentiated flow

Information about vocal loudness and phonation type are reflected in the changes of the glottal closing phase.

The first studies using parameterization of the glottal flow based on amplitude domain measurements was made by Fant & Lin in 1988.

In 1994 Fant et al. introduced the effective declination time and presented a time-domain measure by computing the ratio between two amplitude values, the AC-flow and the derivative of the differentiated flow, eg., the maximum flow declination rate MFDR

Glottal closing phase

NAQ, the normalized AQNAQ, the normalized AQ

AQ

T0Alku P, Bäckström T, Vilkman E. (2002)

In parallel with Fant´s studies,In parallel with Fant´s studies, Alku & Vilkman Alku & Vilkman introduced the introduced the Amplitude Quotient AQAmplitude Quotient AQ in in studies 1996studies 1996

Ûp-t-p

MFDR

Maximum flow declination rate

which normalizes the AQ values with respect to the duration of the fundamental period T0.

Alku et al. found that the AQ parameter systematically reflected changes in phonation mode and that AQ differed between sexes.

What kind of information about voice production

can NAQ give?

It has so far been used in studies about :

Speech

intensity

phonation type

vocal loading

emotional expressions

voice quality

Singing

singing styles

register

Subglottal pressure and NAQ variation in Classically Trained Baritone Singers

Eva Björkner*†, Johan Sundberg†, Paavo Alku

five Swedish professional baritone singers

international opera carriers

age range 29-65 years

A sung diminuendo at a constant pitch while repeating the syllable [pae:]

Sung at three F0 located at approximately 25%, 50% and 75% of their professional pitch range

Ten equally spaced Ps-values were selected from each singers total Ps range.

Au

dio

Pre

ssu

re

Mean Ps for three F0

0

5

10

15

20

25

30

35

40

45

1 2 3 4 5 6 7 8 9 10Pressure number

Pre

ssure

[cm

H2O

]

~139 Hz~196 Hz~277 Hz

Ps means for the 5

singers

Highly structured data

Fundamental frequency and pressure are strongly correlated

Singer 3

y = 2,1124x - 5,9948

R2 = 0,982

0

10

20

30

40

50

60

0 5 10 15 20 25

Mean pressures ~139 Hz

Mea

n pr

essu

res

~27

7 H

z

Singer 4

y = 2,567x - 3,1855R2 = 0,9911

0

10

20

30

40

50

60

0 5 10 15 20 25

Mean pressures ~139 Hz

Mean p

ress

ure

s ~

277 H

z

Singer 2

y = 2,3068x + 0,7386

R2 = 0,9853

0

10

20

30

40

50

60

0 5 10 15 20 25

Mean pressures ~139 Hz

Mean p

ress

ure

s ~

277 H

z

Singer 5

y = 1,9824x - 6,2238R2 = 0,9657

0

10

20

30

40

50

60

0 5 10 15 20 25

Mean pressures ~139 Hz

Mean p

ress

ure

s ~

277 H

z

Singer 1

y = 2,2338x - 2,0326

R2 = 0,9947

0

10

20

30

40

50

60

0 5 10 15 20 25

Mean pressures ~139 Hz

Mean p

ress

ure

s ~

277 H

z

Pressure differences between octaves

0

500

1000

1500

2000

2500

3000

0 5 10 15 20 25 30 35 40

Mean Pressure [cmH2O]

Mea

n M

FDR

[l/

s2]

HIGH

LOW

Means across the 5 singers

MFDR increases with increasing Ps

For the same Ps the low F0 shows higher MFDR-values

=> due to the longer period time

NAQ => Information about phonation type

NAQ decreases with

increasing MFDR

NAQ decreases with

increasing Ps

NAQ differs with F0NAQ differs with F0

NAQ and Pressure

0,00

0,05

0,10

0,15

0,20

0,25

0,30

0,35

0,40

0 10 20 30 40 50 60Pressure [cmH2O]

NAQ

NAQ & MFDR

0,00

0,05

0,10

0,15

0,20

0,25

0,30

0,35

0,40

0 1000 2000 3000 4000MFDR

NA

Q

Open symbol=high F0

Filled symbol= low F0

Higher NAQ-values for higher F0…

-Does that mean that these professional singers change phonation type with increasing F0??!!

Why these differences when we have normalized?!

AQ and Ps

0

0,0005

0,001

0,0015

0,002

0,0025

0,003

0 10 20 30 40 50 60

Pressure [cmH2O]

AQ

AQ & MFDR

0

0,0005

0,001

0,0015

0,002

0,0025

0,003

0 1000 2000 3000 4000MFDR

AQ

AAQQ

Open symbol=high F0

Filled symbol= low F0

What happened?

An effect of the singers´ skill to keep the same phonation type independently of Ps and F0?

AQ should give a steady value if phonation type is kept

# 1 AQ

0

0.0005

0.001

0.0015

0.002

0.0025

0 2 4 6PSEN [cmH2O]

AQ

# 2 AQ

0

0.0005

0.001

0.0015

0.002

0.0025

0 2 4 6

Psen [cmH2O]AQ

#4 AQ

0

0,0005

0,001

0,0015

0,002

0,0025

0 2 4 6 8 10 12Psen [cmH2O]

AQ

# 5 AQ

0

0,0005

0,001

0,0015

0,002

0,0025

0 2 4 6 8

Psen [cmH2O]

AQ

# 3 AQ

0

0,0005

0,001

0,0015

0,002

0,0025

0 2 4 6

Psen [cmH2O]

AQ

NAQ or AQ

Speaker do not have large changes in F0, but change phonation mode

Singers have large changes in F0, but do not change phonation mode => AQ…

Conclusions

The five singer’s Ps data were highly structured

Approximately a doubling of Ps for a doubling of F0

Does AQ more accurately reflect phonation mode than NAQ

?

For the same Ps the low F0 showed higher MFDR-values

For a given Ps increase MFDR increased more at low F0

The End