Middle-ear circuit model parameters based on a population of human ears

Area of Science:

• Biomedical Engineering
• Acoustics
• Otoacoustic Emissions

Background:

• Accurate modeling of the middle ear is crucial for understanding hearing mechanics.
• Previous models often simplified complex structures like the tympanic membrane.
• Human temporal bone data provides a valuable resource for model validation.

Purpose of the Study:

• To develop and validate a circuit model of the human middle ear.
• To assess the model's ability to replicate pressure-to-stapes velocity transfer functions.
• To compare model predictions with various experimental measurements from human ears.

Main Methods:

• A circuit model was adapted from feline studies, treating the tympanic membrane as a transmission line and the ossicular chain/cochlea as lumped elements.
• Model parameters were optimized to match measured pressure-to-stapes velocity transfer functions in 16 human temporal bones (up to 12 kHz).
• Model outputs were compared against velocity ratios and input impedance measurements.

Main Results:

• The model achieved good agreement with magnitude and phase of pressure-to-stapes velocity transfer functions.
• The tympanic membrane transmission line significantly influenced both magnitude and phase responses.
• Model predictions favorably matched velocity ratio data and input impedance measurements, including those from living ears.

Conclusions:

• The developed circuit model effectively represents human middle ear mechanics.
• The model shows potential for approximating the behavior of living human ears.
• A single set of parameters can reproduce the main features of the ensemble measurements up to 10 kHz.