Tuning fork hearing tests: what to expect

If you are suffering from hearing difficulties and your doctor suspects an underlying problem, then you may be given a tuning fork test. Read on to learn how these tests work and what to expect if you are given one.

Tuning forks are a simple way to make an initial assessment of hearing loss at different frequencies and to distinguish between conductive and sensorineural (nerve-related) hearing loss.

• The examiner strikes the fork – a metal handle with a small flat plate at one end and two metal prongs at the other – against the edge of a table to make the prongs vibrate and then holds the flat plate in different places against your head. This does not hurt.

• There are two basic tests: Weber's test and Rinne's test. Both rely on the fact that the inner ear is normally twice as sensitive to sound waves transmitted through the air as to sound vibrations conducted through skull bone. Someone with conductive hearing loss – where something blocks transmission of sound waves from the outer to the inner ear – will be less able to hear environmental noise in the affected ear and so will be more sensitive to sound that is conducted through skull bone.

During a Weber's test, the vibrating fork is placed in the middle of your forehead.

• If you have normal hearing, you should hear the bone-conducted sound in the middle, or equally in both ears.
• If you have hearing loss in both ears, the sound may be muted or you may not hear it at all.
• When there is loss in only one ear, if you hear the sound louder in the affected ear, this suggests conductive hearing loss; if it sounds louder in the better ear, this suggests nerve-related hearing loss.

During a Rinne's test, the vibrating fork is first held on one side against the bony lump just behind your ear, called the mastoid process, and then moved about 8 centimetres (3 inches) away from the ear. You will be asked which sounds louder.

• If you have normal hearing, the sound will be louder when the fork is held in front of your ear and the sound waves are being conducted through air.
• If you have conductive hearing loss, you will hear the sound louder when the fork is pressed against the mastoid process and the sound waves are conducted through bone.
• Confusingly, if you cannot hear at all on one side, you will still experience the bone conduction as louder because the vibrations are transmitted around the skull and heard in the other ear.

Tuning fork hearing tests are simple, quick and painless, making them an excellent tool for the initial assessment of hearing problems.