Hearing Aids

Question 1

What are the types of hearing aid?

Answer 1

Behind the ear 
Bone conduction 
Bone bridge
Middle ear implants
Cochlear implant
Auditory brainstem implant

Question 2

Who are hearing aids not helpful for?

Answer 2

Severe hearing loss
Feedback
Local problems
Patient problems

Question 3

How do bone conduction hearing aids work?

Answer 3

1. Compression + expansion of cochlear shell
2. Ossicles lay behind skull
3. Skull vibrates air column

Question 4

When should bone conduction hearing aids be used?

Answer 4

Ear malformation
Chronic OM
Otosclerosis
Trauma

Question 5

What are the criteria for bone conduction hearing aids?

Answer 5

Conductive hearing loss with AB gap >30dB

Bone > 65 dBHL

Question 6

What is a bone bridge?

Answer 6

A bone conduction hearing aid which does not occlude the ear canal

Question 7

What are indications for a bone bridge?

Answer 7

> 75 years

Bone conduction <45dBHL

Question 8

What are middle ear implants?

Answer 8

Surgically implanted vibrating ossicular prosthetics

Question 9

What is the mechanism of a middle ear implant?

Answer 9

Transducer produces vibrations

Vibration transmits to floating mass transducer

FMT couple to stapes/incus/round window

Question 10

What are indications for a middle ear implant?

Answer 10

Severe sensorineural hearing loss

Conductive hearing loss

Question 11

What are the indications for a cochlear implant?

Answer 11

Unilateral severe deafness (>80dBHL)

Children

Not helped by acoustic hearing aids

Question 12

What are auditory brainstem implants?

Answer 12

Electrodes placed in cochlear nucleus in brainstem

Question 13

What are indications for auditory brainstem implants?

Answer 13

Vestibular nerve damage

Total deafness in both ears