Lecture 22: Hearing Assessment

Question 1

Types of hearing loss?

Answer 1

1. Conductive hearing loss: outer and middle ear
2. Sensorineural hearing loss: inner ear
3. Central deafness or Auditory processing disorder due to abnormal central processing

Question 2

Percepetion of different hearing loss?

Answer 2

Conductive: sounds muffled or dull, may have tinnitus

Sensorineural: Poor discrimination of frequency/speech, distortion, loudness imbalance (non-linear increase in perception) , different frequencies missing, tinnnitus.

Question 3

Causes of Central Auditory Disorders?

Answer 3

1. Peripheral injury
2. Developmental causes
3. Neurological disorders (huntington’s, parkinson’s)

Question 4

Methods of assessing hearing?

Answer 4

1. Behavioral
2. Physiological - can measure brain activity when listening
3. Functional imaging of the brain

Question 5

Behavioral assessments consist of?

Answer 5

Audiometry: pure-tone air and bone conduction, speech

• Needs to be done is a sound proof room using headphones and bone vibrators. Bone vibrators only test the inner ear so are useful for distinguishing between middle and inner ear issues and hence conduction or sensorineural hearing loss.

Question 6

What is speech audiometry/

Answer 6

Speech tests: asseses comprehension and detection of speech

• speech detection thresholds
• speech detection in backgrouns noise
• discrimination of speech (words, sentenced)
• age and language appropriate tests

Question 7

What are the physiological tests available?

Answer 7

Otoscopy can be used to look at the eardrum but we can also use

Tympanometry

- Assesses ear drum mobility (eg. glue ear)

- Asseses middle ear pressure

- Assesses integrity of middle ear muscles and related neural pathways

Question 8

Cochlear implant timeframe?

Answer 8

They work best in young children if implanted before the age of 5 where they undergo a large area of plasticity

They now are even giving them to adults with not only profound but also severe hearing loss