Hearing Tests

Question 1

What is Rinne’s test?

Answer 1

Tuning fork placed over mastoid process until the sound is no longer heard, followed by repositioning just over the external acoustic meatus

Question 2

What does Rinne’s test indicate?

Answer 2

Air conduction is normally better than bone conduction.

If BC > AC, there is conductive hearing loss

Question 3

What is Weber’s test?

Answer 3

Tuning fork is placed in the middle of the forehead, equidistance from patients ears.
Patient is asked which side is loudest.

Question 4

What does Weber’s test indicate?

Answer 4

If there is unilateral sensorineural hearing loss, sound localises to the unaffected ear.
If there is unilateral conductive hearing loss, sound localises to the affected side.

Question 5

What is pure tone audiometry?

Answer 5

Most common method used to assess hearing
Quantifies hearing loss and determines nature.
Headphones deliver electronically generated tones at different sound pressure levels over various frequencies
Air conduction and bone conduction (via mastoid process) are measured.
Results are recorded on a chard - audiograms

Question 6

What are audiograms?

Answer 6

First line investigation when patient complains of hearing difficulties

Question 7

What are the results on an audiogram?

Answer 7

Anything above 20dB is normal
In sensorineural hearing loss, both air and bone conduction are impaired
In conductive hearing loss only air conduction is impaired
In mixed hearing loss both air and bone conduction are impaired with air conduction often being worse.

Question 8

What is tympanometry?

Answer 8

Acoustic impedance audiometry
Objective way of measuring pressure in the middle ear and establishing the cause of conductive deafness

Transmission of sound peaks when middle ear pressure equals ear canal pressure so peak of tympanometry curve reflects middle ear pressure

Probe with airtight seal is introduced into the meatus - measures the proportion of an acoustic signal reflected back at varying pressures

Question 9

What are results of tympanometry

Answer 9

Normal ear will show a normal peak with normal compliance.
Raised peak - more compliance = disruption of ossicles or part of drum is flaccid
Flat graph, fluid in the middle ear makes drum stiff
Shift in peak of curve to left found with negative middle ear pressure