A software formant synthesizer is described that can generate synthetic speech using a laboratory digital computer. A flexible synthesizer configuration permits the synthesis of sonorants by either a cascade or parallel connection of digital resonators, but frication spectra must be synthesized by a set of resonators connected in parallel. A control program lets the user specify variable control parameter data, such as formant frequencies as a function of time, as a sequence of 〈time, value〉 points. The synthesizer design is described and motivated in Secs. I–III, and fortran listings for the synthesizer and control program are provided in an appendix. Computer requirements and necessary support software are described in Sec. IV. Strategies for the imitation of any speech utterance are described in Sec. V, and suggested values of control parameters for the synthesis of many English sounds are presented in tabular form.
Dennis H. Klatt (1980) studied this question.