Round window stimulation with an interface coupler demonstrates proof of concept.

Area of Science:

• Biomedical Engineering
• Otolaryngology
• Acoustics

Background:

• Conductive and mixed hearing loss can be treated by mechanical stimulation of the round window (RW) membrane.
• The floating mass transducer (FMT) is the current standard for RW stimulation but has limitations in sound transmission and positioning.
• An interface coupler (IC) concept aims to overcome FMT limitations by stabilizing the actuator.

Purpose of the Study:

• To evaluate a proof-of-concept interface coupler (IC) for round window (RW) stimulation.
• To compare the acoustic performance of the IC against the conventional floating mass transducer (FMT).
• To determine the potential for IC development in improving cochlear sound transmission.

Main Methods:

• A comparative study in a human temporal bone specimen.
• Utilized a piezoelectric stack actuator connected to a proof-of-concept IC.
• Measured stapes, FMT, and IC actuator velocities using laser Doppler vibrometry.

Main Results:

• The IC demonstrated superior sound transmission, linearity, and a wider frequency range compared to the FMT.
• The IC achieved a larger dynamic range than the FMT.
• Challenges were encountered in stabilizing the external actuator's coupling to the IC prototype.

Conclusions:

• The IC concept shows potential for enhancing cochlear sound transmission via the RW.
• Further design development, particularly for actuator integration and stabilization, is crucial.
• The IC offers a promising alternative to the FMT, potentially improving hearing restoration outcomes.