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

Sensorineural hearing loss: no significant difference between bone and air conduction Conductive hearing loss: bone conduction is better than air conduction

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

Pressure in ear canal = ambient pressure = middle ear pressure Maximum pressure transmitted when ear canal pressure = pressure in middle ear.

Tympanogram: type A Pressure in middle ear = pressure in external auditory canal Compliance Pressure

Tympanogram: Type Ad Peak at 0 Excess compliance Compliance Pressure

Tympanogram: type B Poor compliance of the drum throughout all pressures Compliance Pressure

Tympanogram: type C Pressure in the middle ear is negative Ear drum being sucked in Compliance Pressure

Thank you!