Speech is viewed as the product of passing an acoustic source through the vocal tract """"""""filter"""""""". This project will develop a """"""""palatal microphone"""""""" to permit multiple intra-oral measurements of the sound pressure of speech, thus overcoming deficiencies of current recording technologies. Piezoelectric film of polarized Polyvinylidene Fluoride (PVDF) will be used for multiple oral cavity measurements. PVDF is extremely thin, and has a wide bandwidth and relatively flat frequency response. The palatal microphone will be a 12 sensor array etched into a PVDF sheet on a palatal insert, though the present proposal supports only preliminary work on this array. Array output and the extra-oral speech signal will be processed by microcomputer. The signals will be analyzed as static and dynamic simultaneous phenomena. Static estimation of tract resonances will be made through Fourier analysis, with resonant peaks identified and graphically represented in spatiotopic order. The dynamic analysis will display changes occurring within the array over time, broken down by (a) gradients of pre-definable band-passed signal strength, (b) spectral composition represented as visual color differences, or (c) both signal strength and frequency. The palatal microphone will ultimately be used to examine both steady-state and connected speech.
