A New Trans-Tympanic Microphone Approach for Fully Implantable Hearing Devices

Area of Science:

• Biomedical Engineering
• Otolaryngology
• Acoustics

Background:

• Conventional hearing aids have limitations.
• Fully implantable hearing devices (FIHDs) aim to overcome these drawbacks.
• Current implantable microphones in FIHDs face challenges with sensitivity, body noise, and implantation ease.

Purpose of the Study:

• To introduce and evaluate a novel trans-tympanic microphone for FIHDs.
• To enhance microphone sensitivity and reduce body noise interference.
• To assess the feasibility of utilizing natural ear acoustics for improved sound capture.

Main Methods:

• Developed a new microphone design implanted at the tympanic membrane.
• Measured microphone sensitivity and insertion loss in human cadaveric specimens (0.1–16 kHz).
• Assessed maximum stable gain considering feedback with a round-window-drive transducer.

Main Results:

• The trans-tympanic microphone demonstrated high sensitivity.
• Insertion loss measurements confirmed effective sound transmission.
• Stable gain measurements indicated good performance in situ.
• The design leverages pinna directionality and ear canal resonances.

Conclusions:

• The proposed trans-tympanic microphone shows high-performance capabilities for FIHDs.
• This approach offers a promising solution to enhance hearing aid sensitivity and reduce noise.
• Further research may lead to improved audiological device technology.