10.2 Middle ear - what can go wrong and therapies

Question 1

What are the two types of hearing loss?

Answer 1

Conductive: loss of transmission of sound from the outer to inner ear

Sensorineural: damage somewhere from hair cells to cortex

Question 2

What can cause conductive hearing loss?

Answer 2

Ear wax 
Fluid in the ear (otitis media) 
Otosclerosis (ossicles harden and stiffen) 
Damage to the ossicles 
Perforated eardrum

Question 3

What is the most common cause of hearing loss?

Answer 3

Ear wax (cerumen) blocking the ear canal

Question 4

What produces ear wax?

Answer 4

Cerumenous glands

Question 5

What are the causes of sensorineural hearing loss?

Answer 5

Age related to to loss of hair cells
Acoustic trauma (loud noise damage to hair cells)
Some infections (mumps, meningitis) can cause loss of hair cells from damage to auditory nerve
Drugs
Acoustic neuroma
Congenital abnormalaties

Question 6

What is the hypothesised cause of tinnitus?

Answer 6

due to the synchronous firing of a population of auditory neurons

Question 7

What is Meniere’s disease?

Answer 7

Sudden attacks of dizziness, fluctuating hearing loss and low frequency tinnitus potentially due to the overactivity of middle ear muscles

This pushes on the stapes, cause pressure in the labyrinth to rise

Question 8

What hearing do you tend to lose first?

Answer 8

High frequency