1. Eva Björkner
Helsinki University of Technology Laboratory of Acoustics and Audio Signal Processing
HUT, Helsinki, Finland
KTH – Royal Institute of Technology
TMH – Department of Speech, Music and Hearing
Stockholm, Sweden

2. My background: (except being Swedish)
MSc in voice/singing coaching (1998)
Voice research assistant to Professor Johan Sundberg
From : Teaching singing 75% & research 25%
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.

3. Analysis of 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 !

4. My research: Analysis of voice production in the singing voice
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. 2002) for what purposes can it be used?

5. from very low to extremely high pitches (Hz)
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
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

6. Sound Production Contraction of expiratory muscles
The voice source
The pulsating air through the glottis
Contraction of expiratory muscles
Rise in subglottic air pressure
Escape through glottis
Closure
Bernoulli effect
elasticity

7. Mask or microphone recordings
Flow (Rothenberg mask)
Audio
TEAC Multi channel
digital recorder
Oral
pressure
EGG

8. Inverse filtering of the glottal flow (or sound pressure signal)
By eliminating the contributions from the vocal tract, e.g, the formant frequencies
An acoustic approach to understand vocal fold vibratory patterns
the glottal volume velocity waveform
Parameterization 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

9. Flow glottogram parameters
(Time-based & amplitude-based)
0,002
0,004
0,006
0,008
0,01
0,012
Time [s]
Flow
Peak-to-peak pulse
Amplitude
[Up-t-p]
Time [T0]
Derivative
[MFDR]
Closed phase
Differentiated flow glottgram

10. NAQ = the normalized amplitude quotient
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.
Negative peak of the differentiated flow
Ûp-t-p
(MFDR*T0)
Alku P, Bäckström T, Vilkman E. (2002)

11. Aim: Better understanding of register function in female singing voice
Voice Source Differences Between Registers In Female Musical Theatre Singers Björkner E, Sundberg J, Cleveland T & Stone R. E. accepted for publication in J.Voice
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
High subglottal pressures are known to jeopardize
vocal health in both speech and singing

12. => Register differences
Means across Clear Samples
Glottogram parameters
Control parameter
=> Register differences

13. Same pressure = approximately 11 cmH2O
Register differences

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

15. NEXT: Male musical theatre singers How NAQ varies with pressure and different pitches (Hz)
Articles accepted for publication in
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:
“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

16. Thank you