MATH 190 Lecture Notes - Lecture 17: Hindbrain, Sound, Middle Ear
Document Summary
Sound waves: a disturbance which travels through a medium. The particles oscillate back and forth about their equilibrium, but the disturbance travels. This movement (change of pressure of the air molecules) causes the eardrum to vibrate. Loud sounds (db) are mediated by large waves of compressed air (high amplitude) Soft sounds (db) are mediated by small waves of compressed air (low amplitude) Amplitude is encoded at different locations in the basilar membrane. In low sounds the frequency (hz) is low (the speaker vibrates slowly) In high sounds the frequency (hz) is high (the speaker vibrates fast) Catches sound waves deflecting them in the ear canals to the ear rum (ear shell). Converts vibration to liquid medium via the oval window ( entrance of the cochlea) Lever function: weak vibrations picked up over a large area by the eardrum are transformed to more forceful vibration over the smaller area of the oval window to displace cochlear fluid.
