Engineering Mechanics

Proceedings Vol. 12 (2006)

ENGINEERING MECHANICS 2006

Copyright © 2006 Institute of Theoretical and Applied Mechanics, Academy of Sciences of the Czech Republic, Prague

 

P. Švancara, J. Horáček
pages 366 - +10p., full text

In this study the effect of tonsillectomy on production of Czech vowels is numerically examined. The finite element (FE) models of the acoustic spaces corresponding to the human vocal tracts and acoustic space around the human head are used in numerical simulations of phonation. Models for Czech vowels /a/, /e/, /i/, /o/ and /u/ are analyzed. Similar experimental studies on living subjects are not easily realisable. The acoustic resonant characteristics of the FE models are studied using modal and transient analyses (excitation by a short pulse). The production of vowels is simulated in time domain using transient analysis of the FE models excited by Liljencrants-Fant’s (LF) glottal signal model. Calculated results show that tonsillectomy causes frequency shifts of some formant frequencies mostly down to lower frequencies. Biggest shifts were obtained for 2nd and 3rd formants for vowel /o/ ~300Hz down to lower frequencies and for 2nd (~450Hz) and 3rd (~150Hz) formants for vowel /u/ down too. The frequency shifts of the formants are significantly dependent on position and size of the tonsils.

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