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Flashcards in Audition - Martin Deck (16):

Impendance matching

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


In which direction does the pinna help localize sound?



Inner hair cells

Secrete neurotransmitter onto AFFERENT nerve fibers


Outer hair cells

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


Signal transduction

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


Fourier analysis

Cochlea breaks complex tones down into component sinusoidal waves


Tuning curve

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)


Place coding

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


Volley coding

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


Central processing

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


Thalamic processing

Medial geniculate preserve tonotopy


Tonotopical organization

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


Types of peripheral acquired hearing loss

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


Cochlear implants

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


Penetrating auditory brainstem implants (PABI)

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


Transient evoked otoacustic emissions probe

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