Audition

Question 1

Audition (hearing): central auditory processing

objectives

Answer 1

• Identify anatomy and function of different levels of auditory processing
• Understand how sounds are located
• Recognize what happens when there is damage to different parts of auditory system

Question 2

Answer 2

Question 3

Initial Receiving Centers: Brainstem

Olivary Nucleus function

Inferior Colliculus function

Medial Geniculate Nucleus function

Answer 3

Olivary Nucleus - Detects time differences (L vs R ear arrival time) and intensity (loudness)

Inferior Colliculus - Convergence allows mapping of sounds withing regions of space

Medial Geniculate Nucleus - Located in thalamus. Sensory relay. Convergence allows processing of frequency and temporal (timing between cues) combinations of sounds.

Question 4

Primary Auditory Cortex A1

Answer 4

• conscious sound perception
• located in temporal lobe
• Tonotopic organization of frequency (pitch)
• Organized according to apex and base of cochlea (lower hertz to higher hertz)

Question 5

Damage to outer and middle ear results in ?

Damage to inner ear or auditory afferents results in ?

Damage to auditory cortex results in ?

Answer 5

Outer and middle ear damage = Conduction deafness

Inner ear or auditory afferents damage = Sensorineural deafness

Auditory cortex damage = Central deafness

Question 6

How do hearing aids work?

Answer 6

1. Microphone detects sound
2. Amplifier magnifies sounds electronically
3. Receiver changes electronic impulses back to sound
4. Speaker makes sound

Best for conduction deafness and hearing loss due to normal hair cell decline. Must have enough functioning hair cells.

Question 7

How do cochlear implants operate?

Answer 7

• Best for sensorineural hearing loss, damage to hair cells/cochlea
• Electrical stimulation of the auditory afferents
• Cochlear/Auditory nerve must be intact and functioning
• Possible b/c of tonotopic map of frequency throughout auditory pathway