Multi-pulse LPC modeling of articulatory movements
The frame-by-frame variation of tongue profiles derived from X-ray film data is described in terms of the temporal patterns of four articulatory parameters. The temporal variation of each parameter, i.e., movement, is assumed to be the output of a time-invariant auto-regressive filter. Each filter is excited by a sequence of pulses, representing articulatory commands. The filter coefficients, and the position and amplitude of the pulses are determined by applying an MLPC method. The curve of synthesis error for each movement shows a rapid decrease up to a number of pulses corresponding to that of the syllables in the sentence and then the decreasing rate becomes distinctively slower suggesting the presence of syllable-size motor organization. The minimum number of pulses is determined by using an acoustic criterion. It depends on the number of the phonetic features, in the sentence, of which their realization is crucially related to their pertinent parameters.
multi-pulse lpc syllables speech production articulatory movement modeling