Hearing aid system with 3D sound localization

Many people nowadays suffer from various degrees of hearing impairment. Having an appropriate hearing aid system is a good solution to resolve their hearing problem. In this application, various noises interfere with the hearing aid system to result in degrading sound quality. In order to improve sound quality, the schemes to suppress and remove noises are investigated. Additionally, the sound localization that can enhance the perceptual sensation is implemented. In this work, the microphone array and adaptive beam-forming techniques are explored to suppress noises and improve sound quality. Particularly, the time delay of arrival technique for the recorded sound in five microphones is adopted to effectively determine the location of sound. Since the proposed microphone array is worn on the patient chest, the derived sound location need be transferred to the relationship between ears and sound position, in which the head-related transfer function is employed to yield 3D sound. The simulation results show that noises can be suppressed by around 5dB and the sound location can be determined under a 15-degree deviation. Therefore, the proposed hearing aid system can enable persons who have difficulty in hearing to perceive good sound quality and localization.