促音発話時の構音器官の運動に関する研究

要旨

The pattern of movements of the articulatory organs, particularly the tongue and lips, in the production of Japanese geminate was analyzed using an X-ray microbeam system. Special attention was paid to clarify the difference in the pattern of movements in geminate production from that in simple and long vowel production. The subject was a Japanese male who spoke the Tokyo dialect of Japanese. Goldpellets were attached to the uppersurface of the tongue body and dorsum, lowerlip and lower Jaw using dental adhesive. Another reference pellet was placed on the nasal dorsal, and a goldfilling in the left first upper incisor was also used as a reference. The movement of each pellet during the production of test utterances was tracked using an X-ray microbeam system developed at Wisconsin University and the data output was read into a computer memory core for further analysis. During recording sessions, the subject uttered a series of nonsense test words/papiH/./paHpiH/ and /paQpiH/, where /Q/ indicates a geminate and /H/ indicates a long vowel. A comparison was also made between the utterances produced at the normal speed and those produced at the maximal speed. The movement data were analyzed using a Sun computer system. It was found that the velocity of vertical lip movement was almost constant, regardless of the type and speed of utterance and that the variation in its movement pattern was relatively small. On the other hand, the movement of the tongue body and dorsum was significantly slower and its pattern was more variable in the production of geminate compared with simple and long vowel production. It was concluded that the tongue body and dorsum movements during Japanese geminate production can be regarded as a feature-specified articulator representation called phonological underspecification.

主題