Simulation and measurement of skull vibration with a bone conduction hearing aid

Hearing aid implant is not suitable for little children with congenital aural atresia because their skulls are still growing. Since the critical period of speech and language development is during the first three years of life, the child has to be exposed to verbal stimulation as early as possible. The purpose of this study is to develop an external bone-conduction hearing aid for a newborn child. A headband or spectacle can be used to keep the hearing aid in position. To improve the design of the hearing aid vibrator, finite element analysis was applied to analyze the structure factors that affect the performance of the vibrator. The vibrator and head were simulated as a whole system to acquire more accurate estimation of the spectral response of the bone-conduction hearing aid. The measurement on artificial mastoid shows the vibrator has a wide working range from 200 to 4000 Hz, which covers the most crucial acoustic frequency range for speech recognition. The test of bone conduction hearing aid on adult subjects shows comparative performances with a commercial device. This miniature and low-price bone conduction hearing aid will help the specific group of hearing impaired kids to begin the required early intervention therapy.