Digital-Formant Synthesizer for Speech-Synthesis Studies

Recent work on speech synthesis by rule has led to the design and evaluation of a new digital-formant synthesizer. The synthesizer was simulated on a digital computer at a 20-kHz sampling frequency. The improvements over previous synthesizers include: an excitation source for the unvoiced component of voiced fricatives; a method for producing a voice bar for the closure period of voiced stops; and a simple design for the higher pole correction network that exploits the properties of sampled data systems. Spectrographic examples of synthetic speech are shown in order to illustrate these improvements. A brief discussion of some advantages and disadvantages of serial and parallel synthesizers is presented.