Tests to detect impaired hearing are routinely performed in childhood. All newborn babies are given a hearing screening test, usually using the otoacoustic emission test. Sometimes an auditory brainstem response (ABR) test may also be done. In this test, sounds are played to the baby though headphones while electrodes on the baby’s head and neck detect the brain’s response to the sounds. Further hearing tests are performed as part of the routine developmental assessment and whenever hearing impairment is suspected. Once a child has learned simple language, speech discrimination tests may be performed. By the age of about 4, most children can manage a simple form of audiometry similar to that used to diagnose hearing impairment in adults (see Hearing tests).
This test detects the echo that is normally emitted by the inner ear in response to sound. An earpiece is placed in the ear canal, and a sound is played through it. The resulting echo is recorded. The test is painless.
Speech discrimination tests can be used to detect hearing loss in young children who have a simple vocabulary. For example, the McCormick toy discrimination test is used in children of about 3 years old. The child is shown various toys and is then asked to identify pairs of toys that have similar-sounding names, such as tree and key.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.