INFLUENCE OF THE NASAL CAVITIES TO HUMAN VOICE QUALITY

Nasal cavities (NC) form the side branches of the human vocal tract and exhibit antiresonance and resonance properties which influence the produced voice quality. This study investigates the possibility of these resonances to contribute to the speaker's or singer's formant cluster around 3 - 5 kHz. A reduced finite element (FE) model was created which allows numerical simulation of the effects of changing the volumes of NC on the acoustic resonance and antiresonance characteristics of the vocal tract. This model, created from an accurate three-dimensional (3D) FE model of the human vocal tract for vowel [a:] and [i:] is computationally-effective and allows parametric changes of the volume connecting the nasal tract with the human vocal tract. Developed FE models of acoustic spaces of nasal and vocal tract for vowels /a:/ and /i:/ are used to study the influence of (NC) on phonation of these vowels. Acoustics frequency-modal characteristics are studied by modal analysis and numerical simulation of acoustic signals in time domain is performed by transient analysis of the FE models.