Hearing loss

Question 1

Conductive hearing loss

Answer 1

Sound isn’t transferred effectively to the internal ear

from the external/middle ear

Question 2

Conductive hearing loss - cause

Answer 2

Obstruction in the passage of the external/middle ear 
- blood build up behind ear drum
- effusion 
- CSF 
- foreign body 
Tympanic membrane perforation
Ossicle damage (mainly incus)
Stapes fixation

Question 3

Conductive hearing loss - audiometry (graph) findings

Answer 3

Significant gap between air and bone conduction thresholds

- bone conduction thresholds are within normal limits

Question 4

Sensorineural hearing loss

Answer 4

Damage to the hair cells within the cochlea or CNVIII nerve (or both)

Question 5

Sensorineural hearing loss is permanent/non-permanent?

Answer 5

Permanent

- hearing will not be regained

Question 6

Sensorineural hearing loss - cause

Answer 6

Exposure to loud noise (as cochlear hair cells will be damaged)
- factory work
Age related hearing loss (presbycusis)
Ototoxic drugs (gentamicin)

Question 7

Sensorineural hearing loss - audiometry (graph) findings

Answer 7

No significant gap between air and bone conduction thresholds

Question 8

Sensorineural hearing loss - management

Answer 8

Hearing aids

- this stimulated the hair cells in the cochlea

Question 9

Mixed hearing loss

Answer 9

Combination of conductive and sensorineural hearing loss

- there is damage in the outer/middle ear AND in the inner ear

Question 10

Mixed hearing loss - audiometry (graph) findings

Answer 10

At parts there is a significant gap between air and bone conduction thresholds but bone conduction thresholds are not all within normal limits

Question 11

Audiometry - what is it?

Answer 11

First line test to assess the nature and degree of hearing loss in adults and young children

Question 12

Audiometry - what does it measure?

Answer 12

Measures an individuals hearing sensitivity for calibrated pure tones and testing is carried out over a range of frequencies
The patient responds to sounds they hear by pressing a button

Question 13

Audiometry - measuring air conduction

Answer 13

Use headphones and assess the entire auditory pathway

Question 14

Audiometry - measuring bone conduction

Answer 14

Use a bone conductor and bypass the external and middle ear, stimulating the cochlea directly

Question 15

Audiometry - what is the symbol for air conduction on the right side?

Answer 15

Right = Round + Red

Question 16

Audiometry - what is the symbol for air conduction on the left side?

Answer 16

Left = Blue + Cross

Question 17

What is masking?

Answer 17

Put sound into ear you are NOT testing which distracts that ear whilst the opposite ear is being tested

Question 18

When is masking required?

Answer 18

When there is a difference in hearing thresholds between ears

Question 19

Consequences of not masking

Answer 19

It can give an inaccurate measure of threshold leading to
- incorrect diagnosis
wrong management

Question 20

Tympanometry - what is it?

Answer 20

Measure of middle ear function
Tells you how well the ear drums vibrate
Distinction between sensorineural and conductive hearing loss

Question 21

Tympanometry - what is it a test of?

Answer 21

It is a test of function of the middle ear.

It is not a test of hearing