CSD 212 Lecture Notes - Stapedius Muscle, Mastoid Part Of The Temporal Bone, Bone Conduction
6 Dec 2013
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Document Summary
Traveling wave thru cochlea received @ round window. Tw falls on basilar membrane @ place consistent w/ freq. of signal. Electrical: firing of hair cells @ 8th nerve. Goal: earlier id of infants w/ hearing impairments. Infants who don"t pass screening undergo eval. before 4 mo. age. Examine ear"s response to sound (mini microphone in ear canal) Cone of light on tympanic membrane = no fluid. Elevated threshold (>15db) > problem in any area of ear. Tones presented to bone vibrator behind ear on mastoid bone. Elevated threshold > problems in cochlea or auditory nerve. If bone > air, problem w/ oe or me. If bone = air, problem w/ ie or deeper. When child looks, visual reinforcer animated & lit up. Condition children to do sthg fun in response to sound. Once tone is heard, kids put peg in pegboard, drop block in box, push button. Pure-tone audiograms don"t give info about understanding speech.
