Hearing Loss Flashcards
What is the most common cause of hearing loss (especially in older adults)?
Presbycusis
What is presbycusis?
Gradual, age related SENSORINEURAL hearing loss that occurs due to changes in the inner ear.
2 features of presbycusis?
1) difficulty hearing high-pitched sounds
2) difficulty understanding speech in noisy environments
What are the 2 main categories of hearing loss?
1) conductive
2) sensorineural
What 2 tests can be used to differentiate between conductive & sensorineural hearing loss?
1) Weber’s
2) Rinne’s
How to perform Weber’s test?
1) Strike tuning fork
2) Place it in the centre of the patient’s forehead
3) Ask the patient if they can hear the sound and which ear it is loudest in
What is a normal result in Weber’s test?
The patient hears the sound equally in both ears.
Weber’s test result in sensorineural haering loss?
Sound is louder in the UNAFFECTED ear
Weber’s test result in conductive hearing loss?
Sound is louder in the AFFECTED ear.
This is because the affected ear “turns up the volume” and becomes more sensitive, as sound has not been reaching that side as well due to the conduction problem.
When the tuning fork’s vibration is transmitted directly to the cochlea, rather than having to be conducted, the increased sensitivity makes it sound louder in the affected ear.
How to remember Weber’s test:
Picture Spiderman shooting a web (Weber’s) right in the middle of someone’s face.
How to perform Rinne’s test?
1) Strike the tuning fork to make it vibrate and hum
2) Place the flat end on the mastoid process (the boney lump behind the ear) – this tests bone conduction
3) Ask the patient to tell you when they can no longer hear the humming noise
4) When they can no longer hear the noise, remove the tuning fork (still vibrating) and hover it 1cm from the same ear
5) Ask the patient if they can hear the sound now – this tests air conduction
6) Repeat the process on the other side
Normal result in Rinne’s test?
When the patient can hear the sound again when bone conduction ceases and the tuning fork is moved next to the ear rather than on the mastoid process.
It is normal for air conduction > bone conduction.
What is Rinne’s positive?
A normal result –> when air > bone
What is Rinne’s negative?
An abnormal result - when bone > air
The sound is not heard after removing the tuning fork from the mastoid process and holding it near the ear canal.
What does Rinne’s negative indicate?
A conductive cause for the hearing loss.
Sound is transmitted through the bones of the skull directly to the cochlea, meaning bone conduction is intact.
However, the sound is less able to travel through the air, ear canal, tympanic membrane and middle ear to the cochlea due to a conductive problem.
