PSY BEH 11A Lecture Notes - Lecture 23: Basilar Membrane, Cochlear Duct, Inner Ear

• School: UC-Irvine
• Department: Psychology and Social Behavior
• Course: PSY BEH 11A
• Professor: Bruce Berg

Document Summary

Cochlea (greek for snail), looks like a snail. Very deep in the temporal bones: very protected since they are delicate. Opposition to the flow of energy at the interface of two media with different densities: of all the sound energy, 99. 9% is reflected back a huge loss. When a sound wave encounters a water surface, 99. 9% The inner ear is filled with fluid. Three chambers: scala vestibule, scala media. We want to put some other stuff in there. Special decomposition of the sound: spectral analysis of a sound by well-defined structural features. Stapes (part of the middle ear bones) will vibrate and introduce vibrations into the fluid: helicotrema, cochlear partition = basilar membrane. The tube gets narrower from the base (where the stapes is) to the apex but the basilar membrane is getting wider. Early ages: helmholtz, place = frequency. Helmholtz proposed that the place of local vibrations along the basiliar membrane is dependent on the frequency of the sound.