Investigation of the relationship between structural damage and hearing impairment based on the whole ear model.

Abstract

Background: With the existing experimental techniques, it is unable to measure the overall structural vibration of the human ear, which is difficult to reflect the relationship between hearing and ear structures.

Aims/objectives: The overall biomechanical behaviour of the whole ear structure during sound perception is described.

Methods: Based on CT scanning data and knowledge of ear physiology, a 3D whole ear numerical model was developed that conforms to the actual physiological environment of the human body.

Results: The outer ear canal (EC) has an amplifying effect on sound conduction. The middle-lower part of tympanic membrane (TM) is susceptible to damage, which is mainly reflected in the high-tendency of clinically TM perforation phenomenon. Similarly, TM's damage or hypoplasia is also common. Peak amplitude occurs at the center of one-side of the oval window membrane (OWM) and the center of the round window membrane (RWM), respectively, and these areas are prone to disruption and more severely may evolve into perilymph fistulas. The BM's amplitude changes longitudinally along the cochlear helix as frequency increases.

Conclusions and significance: This model reflects the impact of localized structural damage on hearing under the coordinated working of the whole ear (outer, middle and inner ears).