3D printed dummy heads for crosstalk cancellation studies in bone conduction

Area of Science:

• Biomedical Engineering
• Acoustics
• Audiology

Background:

• Bone conduction (BC) hearing devices can suffer from crosstalk, where sound transmitted to one cochlea is also perceived by the contralateral cochlea.
• This crosstalk interferes with binaural hearing, impacting sound localization and speech intelligibility in noisy environments, especially for BC device users.
• Accurate physical models are needed to study and mitigate BC crosstalk, as direct cochlear measurements in humans are invasive.

Purpose of the Study:

• To develop and validate anatomically accurate 3D-printed dummy heads for investigating bone conduction (BC) crosstalk.
• To assess the effectiveness of a novel crosstalk cancellation technique using these dummy heads.
• To determine if the dummy head model can reliably replicate human responses to BC crosstalk cancellation.

Main Methods:

• Construction of dummy heads using 3D-printed ABS skulls and silicone skins of varying hardness.
• Placement of 3-axis accelerometers at the simulated cochlea location to measure inner ear response.
• Targeting crosstalk cancellation at the mastoid and evaluating its efficacy at the simulated cochlea.
• Comparison of dummy head results with previous human subject experiments measuring hearing thresholds.

Main Results:

• The study successfully constructed functional 3D-printed dummy heads with realistic skull and skin properties.
• The dummy head model demonstrated the ability to simulate and assess BC crosstalk cancellation effects.
• Preliminary comparisons suggest the dummy heads can replicate human responses to crosstalk cancellation strategies.

Conclusions:

• 3D-printed dummy heads offer an accessible and effective platform for researching bone conduction (BC) crosstalk.
• The developed methodology provides a valuable tool for optimizing BC hearing device performance.
• Freely available 3D models encourage further research and replication in the field of auditory prosthetics.