SPEECH SYNTHESIZER HAVING SPEECH TIME STRETCH AND COMPRESSION FUNCTIONS

A speech synthesizer is disclosed with the capability of stretching and compressing the speech time base without changing the pitch of the synthesized speech. One frame of speech is represented during a given time base by LPC parameters which are sampled a constant number of times per frame and stored in memory. Speech is synthesized by fetching each of the stored LPC parameters for each frame and subjecting the parameters to interpolation, synthesizing the interpolated parameters and converting the synthesized parameters to analog format. A decrease in the speed of the reproduced speech is produced by lengthening the time interval of interpolation between the fetching of each of the stored LPC parameters which have been previously stored for each frame. An increase in the speed of the reproduced speech is produced by decreasing the time interval of interpolation between the fetching of each of the stored LPC parameters which have been previously stored in each frame.