Your doctor may recommend hearing tests if you have difficulty hearing speech or if you work in a noisy environment. He or she may perform preliminary tests in the surgery and may refer you to a hearing specialist for others. Some tests determine the type of hearing loss, while others assess how well you can hear sounds of varying frequency and volume. Babies are given a hearing screening test soon after birth; further hearing tests are carried out during childhood as part of routine developmental assessment and whenever hearing impairment is suspected (see Hearing tests in children).
A tuning fork is used to distinguish conductive hearing loss, resulting from a disorder of the outer or middle ear, from sensorineural loss, which is caused by a disorder of the inner ear or of the nerves that transmit hearing to the brain.
Detailed information about the movements of the eardrum and bones of the middle ear in response to sound can be obtained by tympanometry. The test is used to establish the cause of conductive hearing loss and is often used in children because it does not rely on responses from the person being tested.
This test measures how loud a sound has to be for you to hear it. Sounds of varying frequency are transmitted to one ear at a time through headphones. For each frequency, the volume is increased until you hear it, and the results are recorded. The test is repeated with a speaker held against a bone behind the ear.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.