Download - Nottingham SCRUBS

Otology
Eleanor Houghton
Objectives
1. Differentiate between:
a)sensorineural and conductive deafness
b)subjective, objective, physiological and
pathological
tinnitus
2.
The student should be able to perform and
interpret Rinnes and Weber tuning fork
tests
3.
Interpret pure tone audiograms and
tympanograms
Conductive deafness
Conductive hearing loss
•
•
•
•
Otitis media
Foreign body
Perforated ear drum
Otosclerosis
Sensorineural deafness
Sensorineural hearing loss
•
•
•
•
Presbyacusis
Acoustic neuroma
Noise induced hearing loss
Ramsay hunt syndrome
Tinnitus
• Objective: there is an acoustic stimulus which
is generated from within the head
• Subjective: there is no acoustic stimulus
• Physiological: short term tinnitus (<15
minutes) due to excessive hair cell activation
in the cochlear
Rinne’s
• Air conduction vs
bone conduction
• 512Hz tuning
fork
• Place on
mastoid, then 1
inch from
external meatus.
Rinne’s positive
Rinne’s negative
Weber’s
• Compares bone
conduction in both ears
• Place 512Hz tuning fork
in centre of forehead
• Patient asked if the
sounds is louder on a
particular side.
Weber’s: conductive hearing loss
Weber’s: sensorineural HL
Example
• Weber’s lateralises to the L
– ? L conductive hearling loss OR ? R sensorineural
hearing loss
• Rinne‘s - on L
• Rinne’s + on R
• CONDUCTIVE HEARING LOSS ON THE LEFT
Pure tone audiometry
• Type and degree of hearing loss
• Measures the quietest sound a person can
hear and different pitches
• Compares bone and air conduction
Audiograms
Audiograms
• Sensorineural hearing loss: no significant
difference between bone and air conduction
• Conductive hearing loss: bone conduction is
better than air conduction
Example
Example
Example
Example
Example
Example
Tympanometry
• It measures the
pressure in the middle
ear, the compliance of
the tympanic
membrane and the
volume of the external
auditory canal
Tympanometry
Tympanometry
• Pressure in ear canal =
ambient pressure = middle
ear pressure
• Maximum pressure
transmitted when ear canal
pressure = pressure in
middle ear.
Tympanogram: type A
Compliance
• Pressure in middle
ear = pressure in
external auditory
canal
Pressure
Tympanogram: Type Ad
Compliance
• Peak at 0
• Excess compliance
Pressure
Tympanogram: type B
Compliance
• Poor compliance of
the drum
throughout all
pressures
Pressure
Tympanogram: type C
Compliance
• Pressure in the
middle ear is
negative
• Ear drum being
sucked in
Pressure
Thank you!