BIO325H5 Lecture Notes - Lecture 20: Wave, Standing Wave, Kasserine
Document Summary
Is the external part of a mammals ears. Form suggests its function and weather mobility is necessary for them. Has three bones and 2 muscles: ossicles, malleus, and incus stapedius, tensor tympani muscle, and stapedial muscle. The middle ear ossicles matches the impedance of the fluid air and water perilymph of the cochlea. The chin of bones does this by areal ratio: sound is collected over a larger eardrum and concentrated on the smaller oval window at the sapedius footplate. The muscles protect the cochlea since they have intense cries and sensitive ears: stapedius pulls on the stapes and rotates the large amplitudes carried by malleus and incus are expended. Bio325 impedence matching occurs in the middle of the ear while in the katydid it occurs in the fluid filled dispersive medium: impedance matching brings fluctuating forces into the fluid.
