Article
Impact of the Ear Canal Motion on the Occlusion Effect for Bone-Conducted Stimulation (en)
* Presenting author
Abstract:
The occlusion effect denotes the increased low-frequency perception of bone-conducted sounds when the ear canal (EC) is blocked. This study investigates the sound generation due to the structural motion of the EC, accounting for the vibrations of the EC wall, but also for the motion induced by the surrounding tissues at the EC entrance, occluding device medial surface, and tympanic membrane. The EC motion is obtained from a finite element model of a human head excited by a bone transducer. It is utilized as input for a circuit model, which illustrates influencing factors and related mechanisms.The results demonstrate that accounting for a non-compressional motion of the EC may lead to a reduction of the occlusion effect at frequencies below approximately 300 Hz compared to solely considering the deformation of the EC wall. Accordingly, this phenomenon helps to explain the differences between experimental data and previous occlusion effect simulations in this frequency range, highlighting the importance to discern between multiple contributing mechanisms to the sound pressure in the EC.