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 (P s ) 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 parameters (Time-based & amplitude-based) Time [s]

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 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 AQ AQ T0 Alku P, Bäckström T, Vilkman E. (2002) In parallel with Fant´s studies, Alku & Vilkman introduced the Amplitude Quotient AQ in studies 1996 Û p-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 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 P s -values were selected from each singers total P s range. Audio Pressure

P s means for the 5 singers Highly structured data Fundamental frequency and pressure are strongly correlated

Pressure differences between octaves

Means across the 5 singers MFDR increases with increasing P s 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 P s NAQ differs with F0 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 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

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 P s data were highly structured  Approximately a doubling of P s for a doubling of F0  Does AQ more accurately reflect phonation mode than NAQ ?  For the same P s the low F0 showed higher MFDR-values  For a given P s increase MFDR increased more at low F0

The End