Eva Björkner

Helsinki University of TechnologyLaboratory of Acoustics and Audio Signal ProcessingHUT, Helsinki, Finland

KTH – Royal Institute of TechnologyTMH – Department of Speech, Music and HearingStockholm, Sweden

My My background: background: (except being Swedish)(except being Swedish)

MSc in voice/singing coaching (1998)

Voice research assistant to Professor Johan Sundberg

From 1998-2003: Teaching singing 75% & research 25%

HOARSE 100%HOARSE 100%Professor Johan Sundberg, at the dept of

Speech, Music & Hearing, KTH, Stockholm, Sweden is one of the worlds most well know researchers in the field of analysis of the singing voice production.

Vocal tract (VT) Larynx ventricle Pharynx Mouth – tongue & lips Nose cavity - velum

VT shape affects

=> resonance (formant) frequencies

Which generates

different vowels & consonants

!

Analysis of voice productionAnalysis of voice production

Keywords: voice source characteristics inverse filtering formant frequencies the effect of subglottal pressure variation on the voice

source AND..

The Normalized Amplitude Quotient NAQ (Alku et al. The Normalized Amplitude Quotient NAQ (Alku et al. 2002) - for what purposes can it be used?2002) - for what purposes can it be used?

My research:My research: Analysis of voice production in the singing voice

Speech: you decide

when to breathe pitch voice quality loudness

Singing – the music decides!

Entails demand for control of

breathing behaviour Ps

pitch voice quality

Glottal excitation estimation during singing is very challenging because of the wide ranges between extremes:

• from very low to extremely high pitches (Hz)

• from extremely loud to very soft phonations (dB)

• voice qualities – hypo-/hyper functional etc

• registers – differences in vocal fold vibratory pattern

Sound ProductionSound Production

Contraction of expiratory muscles

Rise in subglottic air pressure Escape through glottis Closure

Bernoulli effect elasticity

The voice The voice sourcesource

The pulsating air The pulsating air through the glottisthrough the glottis

Mask or microphone recordings

Flow (Rothenberg mask)

Audio

TEAC Multi channel digital recorder

Oral pressure

EGG

By eliminating the contributions from the vocal tract, e.g, the formant frequencies

An acoustic approach to understand vocal fold vibratory patterns

Inverse filtering Inverse filtering of the glottal flow (or sound pressure signal)

the glottal volume velocity the glottal volume velocity waveformwaveformParameterization of the wave form using time-domain methods corresponds to quantifying the glottal flow using certain quotients:

Closed Q, Closing Q

Open Q, Opening Q,

Speed Q, etc

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

Differentiated flow glottgram

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

Time [s]

Flo

w

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

Time [s]

Flo

w

Peak-to-peak pulse Amplitude

[Up-t-p]Time [T0]

Derivative [MFDR]

Closed phase

Ûp-t-p

(MFDR*T0)

NAQNAQ = = the normalized the normalized amplitudeamplitude quotientquotient

Negative peak of the differentiated flow

Glottal closing phase

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

The amplitude-based NAQ has been found to be more robust than the time-based Closing Quotient, because the extraction of NAQ does not involve the problematic time-instant of the glottal opening.

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

Voice Source Differences Between Voice Source Differences Between RegistersRegisters In Female Musical Theatre In Female Musical Theatre SingersSingers Björkner E, Sundberg J, Cleveland T & Stone R. E. Björkner E, Sundberg J, Cleveland T & Stone R. E.

accepted for publication in J.Voice

High subglottal pressures are known to jeopardize vocal health in both speech and singing

• Analysis: voice source and subglottal pressure Ps characteristics of the chest and head register in the female voice.

• studied by inverse filtering

• a sequence of /pae/ syllables sung at constant pitch and decreasing vocal loudness in each register by seven female musical theatre singers

• ten equidistantly spaced Ps values were selected and the relationships between Ps and several parameters were examined

Aim: Better understanding of register function in female singing voice

Ps [cmH2O]

0

5

10

15

20

25

Mea

n ac

ross

cle

ar c

ases

ChestHead

NAQ

0,00

0,05

0,10

0,15

0,20

0,25

0,30

Mean a

cross

cle

ar

case

s

Means across Clear Samples

=> RegisterRegister differences

Control Control parameterparameter

Qclosed [% ]

0

5

10

15

20

25

30

35

40

45

Mea

n ac

ross

cle

ar c

ases

MFDR [l/ s2]

-350

-300

-250

-200

-150

-100

-50

0

Mean a

cross

cle

ar

case

s

Glottogram Glottogram parametersparameters

0

5

10

15

20

25

30

MAR COX CIE SUB

Qcl

osed

[%]

-50

-40

-30

-20

-10

MAR COX CIE SUB

Soun

d le

vel [

dB]

chesthead

0.00

0.05

0.10

0.15

0.20

0.25

0.30

MAR COX CIE SUB

NA

Q

MAR COX CIE SUB-250

-200

-150

-100

-50

0

MFD

R[l

/s2]

Same pressure = approximately 11 cmH2OSame pressure = approximately 11 cmH2O

Register differences

Qclosed - NAQQclosed - NAQ

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0 10 20 30 40 50

Qclosed [%]

NAQ

The lower NAQ values for chest register suggest a more adducted phonation, as compared to head register.

NEXT: Male musical theatre singersNEXT: Male musical theatre singers How NAQ varies with pressure and different How NAQ varies with pressure and different pitches (Hz)pitches (Hz)

Articles accepted for publication in Articles accepted for publication in the Journal of Voice:the Journal of Voice:

“Voice source differences Between Registers in Female Musical Theatre Singers”

Björkner E, Sundberg, Cleveland T & Stone R.E

“Throaty Voice Quality: subglottal pressure, voice source, and formant characteristics”

Laukkanen A-M, Björkner E & Sundberg J

Article on their way:Article on their way:

“NAQ variation with Ps in Classically Trained Baritone Singers”

Björkner E, Sundberg J & Alku P

“Comparison of two inverse filtering methods for determining NAQ and closing quotient - Voice source characteristics in different

phonation types”

Lehto L, Airas M, Björkner E, Alku P

Thank you

0

10

20

30

40

50

0 5 10 15 20 25 30

Pressure [cmH2O]

QClo

sed [

%]

MARPATSUBCOXCIE