Automatic System for Synthesis-by-Ruale

Abstract

A fully automatic system for conversion of printed text into speech sounds is described. The system is divided into two parts: one part generates prosodic information from programmed rules, and the second part synthesizes the sounds. The sound synthesizer is realized by a programmed articulatory model of the vocal tract [C. H. Coker, J. Acoust. Soc. Amer. 47, 49 (1969)]. This paper focuses mainly on details of prosodic-feature assignment. This part of the system contains a syntax analyzer and a dictionary. Using information from the dictionary, the syntax analyzer assigns a phrase category to each word (subject, verb, object, etc.) and a potential for a pause at every phrase boundary. Each word is then assigned a stress and pitch contour using the pause potentials obtained from the syntax analyzer. In the last stage of the prosody generation, each phoneme is assigned duration, pitch, and intensity controls, compatible with the articulatory model program. In the articulatory model, coarticulation which depends upon phoneme duration is automatically treated. The prosodic-rule program is implemented for time sharing on an on-premises GE-635 computer. This program is linked via a data-communications set to the synthesizer implemented on a DDP-516 laboratory computer.