Finite Element Modelling of a Hearing Contact Lens Coupled to the Middle Ear

Abstract

Hearing contact lens (HCL) is a new type of hearing aid devices. One of its main components is a piezoelectric actuator (PEA). In order to evaluate and maximize the HCL’s performance, a model of the HCL coupled to the middle ear was developed using finite element (FE) approach. To validate the model, vibrational measurements on the HCL and temporal bones were performed using a Laser-Doppler-Vibrometer (LDV). The model was validated step by step starting with HCL only. Then a silicone cap was fitted onto the HCL to provide an interface between the HCL and the tympanic membrane. The HCL was placed on the tympanic membrane and additional measurements were performed to validate the coupled model. The model was used to evaluate the sensitivity of geometrical and material parameters with respect to performance measures of the HCL. Moreover, deeper insight was gained into the feedback behavior, which causes whistling sounds, and the contact between the HCL and tympanic membrane.

Keywords

• piezo-electric actuator
• hearing-aid device
• feedback
• hearing gain
• finite element modelling