TRACK-DRAW - A GRAPHICAL INTERFACE FOR CONTROLLING THE PARAMETERS OF A SPEECH SYNTHESIZER

In this report we describe a graphical interface for generating voiced speech using a frequency-domain implementation of the Klatt (1980) ca scade formant synthesizer. The input to the synthesizer is a set of pa rameter vectors, called tracks, which specify the overall amplitude, f undamental frequency, formant frequencies, and formant bandwidths at s pecified time intervals. Tracks are drawn with the aid of a computer m ouse that can be used either in point-draw mode, which selects a param eter value for a single time frame, or in line-draw mode, which uses p iecewise linear interpolation to connect two user-selected endpoints. Three versions of the program are described: (1) SYNTH draws tracks on an empty time-frequency grid, (2) SPECSYNTH creates a spectrogram of a recorded signal upon which tracks can be superimposed, and (3) SWSYN TH is similar to SPECSYNTH, except that it generates sine-wave speech (Remez, Rubin, Pisoni, & Carrell, 1981) using a set of time-varying si nusoids rather than cascaded formants. The program is written for MATL AB, an interactive computing environment for matrix computation. Track -Draw provides a useful tool for investigating the perceptually salien t properties of voiced speech and other sounds.