The path of a click stimulus from ear canal to umbo.

The path of a click stimulus from ear canal to umbo.
Hear Res. 2017 Jan 10;:
Authors: Milazzo M, Fallah E, Carapezza M, Kumar NS, Lei JH, Olson ES
Abstract
The tympanic membrane (TM) has a key role in transmitting sounds to the inner ear, but a concise description of how the TM performs this function remains elusive. This paper probes TM operation by applying a free field click stimulus to the gerbil ear and exploring the consequent motions of the TM and umbo. Motions of the TM were measured both on radial tracks starting close to the umbo and on a grid distal and adjacent to the umbo. The experimental results confirmed the high fidelity of sound transmission from the ear canal to the umbo. A delay of 5-15 μs was seen in the onset of TM motion between points just adjacent to the umbo and mid-radial points. The TM responded with a ringing motion, with different locations possessing different primary ringing frequencies. A simple analytic model from the literature, treating the TM as a string, was used to explore the experimental results. The click-based experiments and analysis led to the following description of TM operation: A transient sound pressure on the TM causes a transient initial TM motion that is maximal ∼ at the TM's radial midpoints. Mechanical forces generated by this initial prominent TM distortion then pull the umbo inward, leading to a delayed umbo response. The initial TM deformation also gives rise to prolonged...

Source: Hearing Research - January 9, 2017 Category: Audiology Authors: Milazzo M, Fallah E, Carapezza M, Kumar NS, Lei JH, Olson ES Tags: Hear Res Source Type: research