Communication aid utilizing bone-conducted sound via teeth by means of mouthpiece form actuator

Since bone-conducted sound is conveyed to cochlea directly, without passing through eardrum, it is audible even for hard-of-hearing people whose inner ears are still normal. In this study, we utilize bone-conducted sound via teeth so as to support sound communication. We implemented a bone-conducted actuator on teeth, while actuators of prevalent hearing aids are attached to mastoid, forehead or jaw in general. Teeth convey sound excitation more easily, because they are bare bones, not covered with skin. Our communication aid is made in the form of mouthpiece with a dental material, and it can be readily put on and taken off from a tooth. Using this actuator, we attempted to record vibrations of teeth when a subject produces a sound. In addition, we carried out experiments regarding sound lateralization of bone-conducted sound via teeth with this actuator. The result shows that examinees can perceive right and left using bone-conducted sound via teeth. The aim of this study is to suggest a new communication aid system not only for hard-of-hearing people but also for the robust.