Audition - Martin

Question 1

Impendance matching

Answer 1

Improve hearing by focusing signals into a small space (TM)

Question 2

In which direction does the pinna help localize sound?

Answer 2

Vertically

Question 3

Inner hair cells

Answer 3

Secrete neurotransmitter onto AFFERENT nerve fibers

Question 4

Outer hair cells

Answer 4

• Have mostly EFFERENT fibers

- Amplify the signal by adjusting the difference between the two membranes, allowing greater inner hair cell response

Question 5

Signal transduction

Answer 5

Influx of K+ depolarizes the hair cell leading to:

• Voltage-gated Ca2+ channels open
• Influx of Ca2+ causes transmitter release
• Transmitter depolarizes nerve fiber inducing action potential that travels to the brain

Question 6

Fourier analysis

Answer 6

Cochlea breaks complex tones down into component sinusoidal waves

Question 7

Tuning curve

Answer 7

Curve that describes the frequency of the sound that the cell will respond to at different loudness levels (the further cells are apart the greater the difference in tone frequency that they will respond to)

Question 8

Place coding

Answer 8

The brain interprets incoming signals carried by a particular nerve fiber in reference to its specific place on the cochlea

Question 9

Volley coding

Answer 9

A small group of CN VIII axons carry action potentials from the Organ of Corti

Question 10

Central processing

Answer 10

Some inferior colliculus neurons respond to frequency modulated sound while others respond to duration

Question 11

Thalamic processing

Answer 11

Medial geniculate preserve tonotopy

Question 12

Tonotopical organization

Answer 12

Inner hair cells in cochlea that are adjacent to each other have almost the same frequency response properties

Question 13

Types of peripheral acquired hearing loss

Answer 13

Conduction: b/c of wax blockage or ossicle damage
Sensorineural: death of cells in CN VIII or hair cell damage
Presbycusis: B/L hearing loss w/age

Question 14

Cochlear implants

Answer 14

Electrode array is inserted through round window, a speech analyzer breaks down sounds into component tones and stimulates the electrode array to deliver depolarizing pulses at those spots where the cochlea would normally respond to those tones

Question 15

Penetrating auditory brainstem implants (PABI)

Answer 15

Used when CN VIII fibers in the organ of corgi are missing or non-functional

Question 16

Transient evoked otoacustic emissions probe

Answer 16

Miniature sound source and microphone transducers detect whether ear can pick up sound