mnsr 27 - sound amplification

Question 1

auditory response

Answer 1

Ears are more sensitive to some frequencies that other even with those at the same intensity but we’ll perceive them as different loudness.( perceived loudness is NOT intensity )

Question 2

loudness is measured by

Answer 2

Phon ( dBHL )
= dBSIL x the function that mimics the frequency sensitivity )
The dBHL scale compares the loudness with a 1Khz of an intensity.
At 1 KHZ of dBhl = dbsil

Question 3

threshold of audibility rises with

Answer 3

age due to presbycus

Question 4

Sound amplification in three mechanisms

Answer 4

to convert sound vibrations into nerve signals
1- ear drums area is half the ear canal so intensity x2 ( hence the smaller area)
2- ossicles work as levers and increases the force by x2
3- the eardrum is 20x more than the oval window
so 2 x 2 x 20 = 80 times or 19 dbSIL )
ossifies transforms low force and high amplitude to high force low amplitude at oval window

Question 5

Basilar membrane is a

Answer 5

resonance structure

Question 6

highest frequencies detected at

Answer 6

near oval window