A quasiarticulatory approach to controlling acoustic source parameters in a Klatt-type formant synthesizer using HLsyn

The HLsyn speech synthesizer uses models of the vocal tract to map higher-level quasiarticulatory parameters to the acoustic parameters of a Klatt-type formant synthesizer. The benefits of this system are several. In addition to requiring a relatively small number of parameters, the HLsyn model includes constraints on source-filter relations that occur naturally during speech production. Such constraints help to prevent combinations of sources and filter that are impossible to achieve with the human vocal tract. Thus, HLsyn could lead to reductions in the complexity of formant synthesis and result in better quality synthesis. HLsyn can also be a useful tool for speech-science education and speech research. This paper focuses on the generation of acoustic sources in HLsyn. Described in detail are the equations and methods used to estimate Klatt-type source parameters from HLsyn parameters. Several examples illustrating the generation of source parameters for obstruents (voiced and voiceless) and sonorants are provided. Future papers will describe the filtering components of HLsyn.