NEW NONSTATIONARY TECHNIQUES FOR THE ANALYSIS AND DISPLAY OF SPEECH TRANSIENTS
Lund LH · 1990
A new nonstationary analysis technique is applied to speech with encouraging results. This technique makes use of a generalized time-frequency representation (GTFR) which uses a kemel that allows finite-time support while suppressing interference terms. This kernel has a cone shape in the (t,z) plane, where t is time of a signal and z is an autocomlation-lie lag. The processing thus allows time and frequency resolution equivalent to the Wigner distribution, but does not have significant interference terms. We show that the effect of this distribution on the long term (1.5 second) display of speech is a visible enhancement of formant tracks. Potentially more important shorter-term (30 milliseconds or less) advantages are illustrated and quantified as more accurate locations of bursts in the time-frequency distribution. We also show that the GTFR technique offers a representation which is less sensitive to threshold settings and is thus morc robust.