Optimization of Yoke Structure in Electromagnetic Vibration Devices

Abstract

　One type of electromagnetic vibration devices is the bone conduction devices. It utilizes bone-conducted sound transmitted through bones and is expected to be used in hearing aids and noise reduction due to the difference in sound propagation paths. However, since the skull is vibrating, a large thrust force is required. In this paper, we examine increasing the power output of electromagnetic bone-conduction devices. The analysis method combines magnetic field analysis and structural analysis to derive the vibration acceleration level, which is an evaluation parameter of bone conduction devices. In this analysis, we focused on the yoke shape to improve the output and changed the device shape.