Bone conduction in Thiel-embalmed cadaver heads.

Area of Science:

• Biomedical Engineering
• Otolaryngology
• Anatomy

Background:

• Bone conduction (BC) hearing is crucial for diagnostics and hearing aids.
• Studying BC-induced middle ear motion typically uses cadaver models.
• Existing models lack consistency with living subjects.

Purpose of the Study:

• Evaluate Thiel-embalmed whole-head specimens for middle ear motion research.
• Assess linearity, reproducibility, and consistency with existing data.
• Determine the viability of Thiel-embalmed models for BC stimulation studies.

Main Methods:

• Laser Doppler vibrometry used on Thiel-embalmed whole-head specimens.
• Measured displacement of skull, umbo, cochlear promontory, stapes, and round window.
• Stimulation via a bone-anchored hearing aid (Baha®).

Main Results:

• Thiel model promontory velocity comparable to Non-Thiel embalmed heads.
• Stapes-to-promontory velocity in Thiel heads matches fresh cadavers.
• Umbo velocity in Thiel heads is similar to living subjects.
• Linear response across stimulation levels and low measurement variability observed.

Conclusions:

• Thiel-embalmed human whole-head specimens are a suitable alternative model for studying BC-induced middle ear mechanics.
• Model findings are consistent with fresh cadavers and living subjects.
• Frequency-dependent differences between the model and living subjects warrant consideration.