LATTICE FILTER FOR WAVEFORM OR SPEECH SYNTHESIS CIRCUITS USING DIGITAL FILTER

摘要

The appts. generates data that represent the instantaneous values of signal representing speech from data that represents the instantaneous values of an excitation signal. This signal is selected from one of two sources which are respectively, a voicing and unvoicing source. The excitation signal is altered by a lattice filter whose coefficients are periodically updated e.g. every 5 ms to reflect the changing shape of the vocal track. A digital feedback loop with a store enables data occurring at various different times to be available to other times.