Auditory

Question 1

What is sound?

Answer 1

Sound refers to pressure waves generated by vibrating air molecules

Question 2

Physical aspects of sound

Answer 2

Air- 340 m/s 
Water- 1500m/s
Glass- 5300m/s 
Light- 
Air- 300,000 km/s

Question 3

Sensitivity to sound- amplitude

Answer 3

Using the magnitude estimation method, subjects report perception of loudness function to the sounds physical intensity expressed as a proportion of sound intensity. (40 DB sound pressure level- SPL)

Question 4

Sensitivity to sound- frequency

Answer 4

Human audible spectrum ranges from 20 to 20,000 HZ

• the sensitivity is greatest in the range of 500 to 5000HZ.
• small animals generally hear higher frequencies, because of cochlea or small animals is smaller and resonates better at high frequencies

Question 5

Sensitivity to sound- pitch and timbre perception

Answer 5

Pitch: property or auditory sensation regarding sound may be offered from their musical scale (low to high). It closely relates to physical properties or fundamental frequency.

Timber- when two tones have the same loudness, pitch, duration but sounds different

Question 6

Sound waves and complexity

Answer 6

Frequency- (pitch) nb cycles per second hertz

Amplitude- (loudness) sound pressure level: DECIBEL (db)

A relative unit defined by the sensitivity of human hearing- OdB~ 2.10-5 pascal (newtons m-2) unit of pressure.

Sounds that consist of sine wave are known as pure tones.

Sound complexity- most sounds = complexes made up of one frequency and several harmonies of the fundamental.

Question 7

Sound legislation 1- binimaurql cues

Answer 7

• azimuth- elevation
• neurone in the medical supervisor olive ( MSO) com location of sound by acting coincide detectors.
• the systematic variation delay lengths/ lines are two impute that work effectively to create a map of sound.
• neutron E would be most sensitive to sound
• sounds have high levels of intensity

Question 8

Auditory system- outer, middle and inner ear

Answer 8

Outer ear- gathers sound
• pinnacle, tympanic membrane

Middle ear- mechanical transformer
• ossicles, malleus, incus, stapes, footplate connected to the oval window

Inner ear- where auditory receptors are located
• semicircular canld, vestibule, cochlea

Question 9

How do we capture sound

Answer 9

High frequency- greatest vibration near membrane

Base and low frequency- greatest vibration near the ape

The basilar membrane has a frequency to place conversion for pure tone stimuli

Question 10

Organ of corti

Answer 10

• the inner ears receptor= the organ of Corti
• corti contains 16000 hair cells in four rows. A single Raw of the inner ear and the three in the outer hair cells
• afferent axons to cochlear nucleus end on inner hair cells.
• efferent axons largely innervate outer hair cells

Question 11



Auditory system two- hair cells, transduction and cochlear amplifier

Answer 11

• hair cells transform mechanical energy into neural signal
• The displacement of the stereocilia open K + channels. FaceTime opens CA + + channels in the cell space which causes neurotransmitter release to excites axons whoar cell bodies are in the spiral or cochlear ganglion