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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. Analysis of voice production. Vocal tract (VT) Larynx ventricle
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Eva Björkner Helsinki University of TechnologyLaboratory of Acoustics and Audio Signal Processing HUT, Helsinki, Finland KTH – Royal Institute of Technology TMH – Department of Speech, Music and Hearing Stockholm, Sweden
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 !
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?
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
Sound Production 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
Flow (Rothenberg mask) Audio Oral pressure TEAC Multi channel digital recorder EGG Mask or microphone recordings
Peak-to-peak pulse Amplitude [Up-t-p] Time [T0] Flow 0 0,002 0,004 0,006 0,008 0,01 0,012 Time [s] Closed phase 0 0,002 0,004 0,006 0,008 0,01 0,012 Flow Derivative [MFDR] Time [s] Flow glottogram parameters (Time-based & amplitude-based) Differentiatedflow glottgram
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)
Voice Source Differences Between Registers In Female Musical TheatreSingers 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 vocalloudness 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
Glottogram parameters Means across Clear Samples Control parameter => Register differences
Same pressure = approximately 11 cmH2O Register differences
NAQ variation with Ps in Classically Trained Baritone Singers Björkner E, Sundberg J & Alku P Filled symbols= ~139 Hz Open symbols= ~278 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 Articles 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 An overview: the use of the NAQ paramete in voice source analysis To be presented in Finnish-Swedish Voice meeting in Tampere 5-6 nov -04