Abstract:

HLsyn is a quasiarticulatory speech synthesizer in which a small set of parameters control a Klatt synthesizer [Stevens and Bickley, J. Phon. 19 (1991)]. Originally, ten parameters were used. In this paper three new physiologically based parameters, together with some additional modifications, are described. The first is a time-varying subglottal pressure parameter, which provides the user with additional control of the voice-source amplitude. It can also be used to turn on voicing, and it has an influence on fundamental frequency. The second parameter is a time-varying percentage change in the compliances of the vocal-tract walls and vocal folds. This parameter can, for example, be employed when synthesizing voiced obstruents: increasing it results in facilitation of glottal vibration and lowering of the fundamental frequency. The third parameter is the time-varying cross-sectional area of a posterior glottal chink. Because it is independent of the area at the membranous folds, significant noise-source amplitudes can be achieved during voiced speech. Thus one can synthesize aspirated voiced stops, as well as breathy speech, in a natural manner. Finally, a default female voice and an intrinsic pitch feature have been added to the system. Examples of copy synthesis where the new parameters play a role are presented. [Work supported by NIH Grant MH52358.]