Some experiments with an area function dyad synthesizer
Richard A. Gillmann · The Journal of the Acoustical Society of America · 1978
An area function dyad synthesis procedure is described which is based on an area function model representing the vocal tract as a set of 14 cross-sectional areas. Area functions representing phoneme steady states (nuclei) and transitions between any ordered pair of phonemes (dyads) are stored in a dyad table. Given an input phoneme string, the synthesizer selects the corresponding sequence of nuclei and transitions and interpolates between each of the 14 cross-sectional areas, producing a model of the shape of the vocal tract changing in time. The filtering process of this vocal tract model is identical to the optimum inverse filter of linear prediction analysis, allowing direct conversion to linear predictive coding (LPC) synthesis. Experiments were performed which tested the effect of varying certain attributes of the synthesizer, viz., linear versus spline interpolation, one point versus three point transitions, nucleus versus no nucleus, and different gain roles. Results will be discussed and a tape played. [Work supported by Rome Air Development Center under Contract No. F30602-77-C-0056.]