Physiology of Hearing

Question 1

What does frequency dictate?

Answer 1

pitch

Question 2

What does amplitude dictate?

Answer 2

intensity

Question 3

What type of sounds are S, D and T?

Answer 3

high frequency

Question 4

How does the ossicular chain act to transmit sound?

Answer 4

acts as a lever arm with varying efficiency depending on the frequency of sound

Question 5

What opens the cartilagenous part of the Eustachian tube?

Answer 5

levator palatine

tensor veli palantini

Question 6

What happens if there is a eustachian tube dysfunction?

Answer 6

negative middle ear pressure

Question 7

What is the role of the oval and round windows of the cochlea?

Answer 7

allow the transmission of pressure waves in enclosed canals

when the oval window goes in, the round window expands

Question 8

Where is low frequency heard in the cochlea?

Answer 8

apex

Question 9

Where is high frequency heard in the cochlea?

Answer 9

base

Question 10

How are sound waves transmitted to the oval window?

Answer 10

through perilymph fluid

Question 11

What are the 3 fluid filled compartments of the cochlea?

Answer 11

Scala Tympani
Scala Vestibuli
Scala Media

Question 12

How many turns are there on the apex of the cochlea?

Answer 12

2.5

Question 13

Which of the fluid filled compartments are filled with perilymph?

Answer 13

scala vestibuli

scala tympani

Question 14

Which of the fluid filled compartments are filled with endolymph?

Answer 14

scala media

Question 15

What fluid filled compartment makes up the vestibular duct?

Answer 15

Scala Vestibuli

Question 16

What fluid filled compartment makes up the tympanic duct?

Answer 16

Scala Tympani

Question 17

What fluid filled compartment makes up the cochlear duct?

Answer 17

scala media

Question 18

How are the perilymph ducts continuous with each other?

Answer 18

Helicotrema

Question 19

What seperates the Scala media and Scala Tympani?

Answer 19

basilar membrane

Question 20

What contains the organ or Corti?

Answer 20

basilar membrane

Question 21

What is the function of the organ of Corti?

Answer 21

connecting mechanica ossilations to electrical impulse transmitted by the vestibuarcochlear nerve

Question 22

What is the role of the outer hair cells?

Answer 22

to support and modulate

Question 23

What is the role of the inner hair cells?

Answer 23

recieve sound through the bending of stereocilia when the basilar membrane deplaces downwards, causing K channels to open and therefore depolarise

Question 24

Where does the action potential hit when it comes along the vestibulocochlear nerve?

Answer 24

E.coli
Coclear nuclei
superior Olivary complex
Lateral lemniscus
Inferior coliculus 
then: primary auditory cortex

Question 25

At what week should a foetus be able to hear?

Answer 25

18 weeks

Question 26

At what week will a foetus respond to sound/voice?

Answer 26

26 weeks

Question 27

How is profound hearing loss usually identified?

Answer 27

newborn screening tests - clicks stimulate hair cells

Question 28

What are the milestones of hearing?

Answer 28

3 weeks - recognise mothers voice
6 months - babbling, turns to noise
12 months - may make simple noises
12-24months - simple words, syllables
18 months - few words
24 months - 50+ words, understands questions
36 months - sentences