Eardrum and columella displacement in single ossicle ears under quasi-static pressure variations.

Eardrum and columella displacement in single ossicle ears under quasi-static pressure variations.
Hear Res. 2018 May 19;:
Authors: Claes R, Muyshondt PGG, Van Assche F, Van Hoorebeke L, Aerts P, Dirckx JJJ
Abstract
Although most birds encounter large pressure variations during flight, motion of the middle ear components as a result of changing ambient pressure are not well known or described. In the present study, motion of the columella footplate and tympanic membrane (extrastapedius) in domestic chickens (Gallus gallus domesticus) under quasi-static pressure conditions are provided. Micro-CT scans were made of cadaveric heads of chickens under positive (0.25 kPa, 0.5 kPa, 1 kPa, and 1.5 kPa) and negative (-0.25 kPa, -0.5 kPa, -1 kPa, and -1.5 kPa) middle ear pressure. Both extrastapedius and columella footplate displacements show a non-linear S-shaped curve as a function of pressure indicating non-linear response characteristics of the middle ear components. The S-curve is also seen in mammals, but unlike in mammals, the lateral piston-like displacement of both the columella footplate and extrastapedius, which is caused by an increased middle ear pressure are smaller than the medial piston-like displacements, caused by a decreased middle ear pressure of the same magnitude. Columella footplate piston displacements are always smaller than the extrastapedius piston displacements, indicating the flexibility of the ex...

Source: Hearing Research - May 19, 2018 Category: Audiology Authors: Claes R, Muyshondt PGG, Van Assche F, Van Hoorebeke L, Aerts P, Dirckx JJJ Tags: Hear Res Source Type: research