Immersed acoustic black hole as a travelling wave absorber: understanding artificial cochlear mechanics

Simon Foucaud , Guilhem Michon (1) , Yves Gourinat (1) , Adrien Pelat (2) , François Gautier (2)

1 ICA - Institut Clément Ader
2 LAUM - Laboratoire d'Acoustique de l'Université du Mans

Inner ear is constituted of fluid-filled ducts partitioned with an elastic structure, the organ of Corti. When the ear is excited by sound, travelling waves appear along the organ of Corti and stimulate the sensory cells. A peak of vibration is reached at a particular place depending on the excitation frequency. The waves are strongly attenuated after this place. Due to the complexity of in vivo experimentations, some aspects of physiological functions still need to be investigated. For this purpose, an experimental setup reproducing the passive behavior of the inner ear has been manufactured. Standing waves are usually observed on artificial cochlea devices due to wave reflection on boundaries. Acoustic black holes are known as vibration absorbers for thin structures. In this paper, an immersed acoustic black hole is used to reduce the reflected wave. Experimental results are compared with a model using the impedance matrix method. Travelling waves can be observed and this device should allow better understanding of artificial cochlear mechanics.

Domaines: Acoustique [physics.class-ph]

Simon Foucaud, Guilhem Michon, Yves Gourinat, Adrien Pelat, François Gautier. Immersed acoustic black hole as a travelling wave absorber: understanding artificial cochlear mechanics. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810956⟩