Relationship between vowel articulation and pitch control

要旨

Extrinsic muscles of the tongue and larynx influence laryngeal function through their effects on the hyoid-larynx complex, and thus cause interaction between vowel articulation and fundamental frequency. It has been argued that the mechanism for pitch control by the extrinsic frame of the larynx is related to vertical movement of the larynx, although physiological data has not always supported this view. In this study, positional control of the hyoid bone was examined by monitoring electromyographic activity from suprahyoid muscles and displacements of the hyoid bone. A speaker produced Japanese two-mora words /ia/ and /at/ with different accent types. The data showed that activity of at least one anterior suprahyoid muscle, the geniohyoid, actively participated in pitch raising by producing anterior movements of the hyoid bone. This result suggests that horizontal rather than vertical movements of the hyoid bone caused by contractions of anterior suprahyoid muscles are used to tilt the thyroid cartilage forward and increase the longitudinal tension of the vocal folds. [Work supported by NINCDS.]

主題