VIII Vestibulocochlear (Acoustic)
The auditory nerves subserves both hearing and vestibular
- mask the opposite ear and whisper numbers. The patient
should not be able to read your lips. Ask the patient
to repeat the numbers. If they cannot do so, increase
the volume of your voice and repeat as needed. Note
- compare air versus bone conduction using the Rinne
test. Apply the vibrating fork against the mastoid
process. Utilize the 512 Hertz tuning fork. Ask the
patient when they can no longer hear it, then place
it in front of the ear.
- test for lateralization using the Weber
test. Apply the vibrating tuning fork to the center
of the forehead and ask the patient where they hear
2. Vestibular Function:
- the vestibular component of the auditory nerve is
tested by observing for nystagmus when extraocular
movements are assessed.
- Rinne air conduction (perceiving the sound
of the tuning fork in front of the ear) is greater
than bone conduction (with the tuning fork held against
the mastoid process).
- Weber normally, patients will either hear
it equally from both ears or respond that they are
- Rinne: in conductive hearing loss, bone conduction
is greater than air conduction. In sensorineural deafness,
air conduction is greater than bone conduction.
- the Weber is abnormal if the patient clearly lateralizes
it to one ear. With a conductive hearing loss, the
patient lateralizes the sound to the affected ear.
With sensorineural deafness the sound is best heard
by the non-involved ear.