Proposal of a wavelet model for vocalic speech coarticulation
Robert Lange · The Journal of the Acoustical Society of America · 1993
A recent development in the theory of wavelets is wavelet system characterization [R. K. Young, WaveletTheoryanditsApplications (Kluwer, Boston, 1993)]. In wavelet system theory, the wavelet transform can be used to describe the time-frequency behavior of a transmission channel, by virtue of its ability to describe the time-frequency content of the system’s input and output signals. The present research proposes a wavelet-system model of speech production; wherein, the system is the process of transformation from one speechstate to another. The transmission channel generates an effected utterance from a control utterance. A speech production effect (such as voice quality, or the influence of the speaker) is thereby characterized in a time-frequency manner. The effect of CVC coarticulation is investigated in particular, using samples of real speech. In this case, an isolated vowel utterance (the control) is contrasted with an utterance of the same vowel imbedded within a /C–C/ context (the effected). The channel thus describes (in terms of wavelets) the CVC coarticulation. [Work supported by Appl. Res. Lab.]