Abstract
The purpose of this study was to investigate articulatory movements of tongue and mandible on pronouncing /S/ sound by analysing the timing of articulation and the pattern of tongue-palate contact. The lingual articulation, mandibular movements and speech sound of ten subjects were simultaneously recorded with an electropalatograph and a mandibular kinesiograph.
Results
1. The timing of lingual and mandibular articulation on pronouncing /S/ was generally constant regardless of sounds and was obtained on the average as follows:
(1) The closing movement of mandible began about 110 msec before (V 1), the offset of preceding vowel and tongue-palate contact began about 40 msec before (V 1).
(2) The mandible reached the closest speaking level about 10 msec after (V 1) and the tongue formed the maximum constriction about 20 msec after (V 1).
(3) The opening movement of mandible began about 30 msec before (V 2), the onset of following vowel and releasing the maximum constriction began at the same time.
2. As regards analysing the pattern of tongue-palate contact by numerical methods, there was individual variability in the pattern, but several characteristics among subjects were found as follows:
(1) The variability of the pattern with the same subject and sound was small.
(2) The perturbation of the pattern by the adjacent vowel was greater at the posterior portion of palate as compared with the anterior.
(3) The influence by the preceding vowel at the forming time of the constriction and the influence by the following vowel at the releasing time was recoginized.
(4) The pattern of tongue-palate contact for the muximum constriction was generally constant regardless of sounds except [ASK].
