[PARCOR analysis in experimental plate wearer's sound and its application to evaluation of plate formation]

The study demonstrates the relationship between palatal formation and human utterance by PARCOR analysis. PARCOR (partial autocorrelation) coefficient 'k' in speech wave was derived from the conception of linear prediction of human speech production by ltakura. Linguistic opposition was also adapted for the evaluation of plate forms and postions. Investigations were conducted to six adult men as the subjects who wore the experimental plates divided by four steps. PARCOR coefficients of the plate wearer's sounds were shifted as the plate area increase, and linguistic oppositions were individually proposed. Conclusions were represented as follows; Phonetic opposition of /p/X/m/ and /d/X/m/ (in 'stop' to 'nasal' opposition) were influenced by the width of the plates. Opposition of /t/x/s/ (in 'stop' to 'fricative' opposition) was significantly influenced by the frontal positions in oral cavity. Phonetic oppositions were also influenced from vowel environments to the consonants. As the plate areas were increased in order of full plate, 1/2 plate and 1/4 plate, the evidency of the oppositions were decreased.