FE Modeling of Human Vocal Tract Acoustics.

Part II: Influence of Velopharyngeal Insufficiency on Phonation of Vowels

Developed FE models of acoustic spaces of nasal and vocal tract for vowels /u:/, /a:/ and /i:/ are used to study the influence of velofaryngeal insufficiency 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. The vocal tract is excited by time dependent airflow at the position of vocal folds, and the time and frequency responses are calculated near the lips and nose. The theoretical results are partly compared with acoustic measurements on physical models designed by the rapid prototyping technique from the FE models, and by clinical investigation.