Hoarse meeting in Liverpool April 22, 2005

1. 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 Hoarse meeting in Liverpool April 22, 2005

2. Voice production Sound => vowels and consonants Oscillation =>pulsating air flow => voice source Air => Subglottal pressure (Ps)

3. Flow (Rothenberg mask) Audio Oral pressure TEAC Multi channel digital recorder Inverse Filtering DeCap – Svante Granqvist

4. Peak-to-peak pulse amplitude Time [T0] Flow Ûp-t-p 0,002 0,004 0,006 0,008 0,01 0,012 Flow Derivative 0,002 0,004 0,006 0,008 0,01 0,012 Derivative [MFDR] Time [s] Flow glottogram parameters (Time-based & amplitude-based) Time [s]

5. Glottal closing phase Information about vocal loudness and phonation type are reflected in the changes of the glottal closing phase. Negative peak of the differentiated flow 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

6. Ûp-t-p MFDR Maximum flow declination rate AQ T0 In parallel with Fant´s studies,Alku & Vilkman introduced the Amplitude Quotient AQ in studies 1996 Alku et al. found that the AQ parameter systematically reflected changes in phonation mode and that AQ differed between sexes. NAQ, the normalized AQ which normalizes the AQ values with respect to the duration of the fundamental period T0. Alku P, Bäckström T, Vilkman E. (2002)

7. 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

8. 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

9. Audio Pressure A sung diminuendo at a constant pitch while repeating the syllable [pae:] • Ten equally spaced Ps-values were selected from each singers total Ps range. • Sung at three F0 located at approximately 25%, 50% and 75% of their professional pitch range

10. Ps means for the 5 singers Highly structured data Fundamental frequency and pressure are strongly correlated

11. Pressure differences between octaves

12. 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

13. NAQ => Information about phonation type NAQ decreases with increasing Ps Open symbol=high F0 Filled symbol= low F0 NAQ decreases with increasing MFDR NAQ differs with F0

14. 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?!

15. AQ Open symbol=high F0 Filled symbol= low F0

16. 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

18. NAQ or AQ Speakerdo not have large changes in F0, but change phonation mode Singers have large changes in F0, but do not change phonation mode => AQ…

19. Conclusions • The five singer’s Ps data were highly structured • Approximately a doubling of Ps for a doubling of F0 • For the same Ps the low F0 showed higher MFDR-values • For a given Ps increase MFDR increased more at low F0 • Does AQ more accurately reflect phonation mode than NAQ ?

20. The End