Time-Frequency Analysis of Vocal Fold's Onset

It is proposed to use time-frequency analysis of vocal fold's onset signal for diagnosis of different phonation disorders evoked by patho- logical changes. The vibration signals are acquired by direct optical inspection of the glottis using an endoscope and a high speed CCD camera system. Because of their outstanding performance the Wigner distribution is used as an analysis tool. It is shown that smoothed versions of the pseudo Wiper distribution are especially well suited from a practical point of view. Application of cone and re- duced interference kernels is considered. It is de- scribed how characteristic features of the time- frequency distribution can be obtained and inter- preted for diagnostics.