抄録
The purpose of this paper is to discuss the possibility of application of ultrasonic technique to observe tongue shape. One of the advantages of ultrasonic technique is harmlessness to the human subject. Beside this, the frontal section of the tongue which is the difficult object for ordinary X-ray photo can be visualized. Sagittal contours of the tongue for five Japanese vowels observed by this method are well corresponding to those by X-ray technique. Contours of the frontal section at around the tongue root show a groove formation during /i/, /e/, and /o/ production.
For all of these three vowels, the genioglossus muscle shows higher activity. Therefore, the observed groove may be representing the inserting portion of the genioglossus muscle.
Since the apparatus we used in this study is designed and developed for the clinical purpose, for example to examine the thyroid tumor, the data we got had limited informations especially, the visualized area was narrow. But if we can use the sector type porbe instead of the linear type, we might have the wider area to be observed.
The ultrasonic apparatus would be appropreate for observation of the tongue shape.
