Types of Hearing Tests

Most audiologists will use several different tests to get a complete picture of your child's hearing. Some tests can be used for all ages of children, while others are used based the child’s developmental stage.

Infants

Evoked otoacoustic emissions (EOAE)

This test uses a tiny, flexible plug that is inserted into the baby's ear canal. The audiologist sends sounds through the plug. A microphone in the plug records the otoacoustic emissions (responses) from the inner ear in reaction to these sounds. When the emissions are present it usually means that the hearing is normal. There may be many reasons why we are not able to measure emissions, including hearing loss. This test is painless and we usually complete it within a few minutes, while the baby sleeps or is very quiet.

Auditory brainstem response (ABR)

This hearing test uses small disk-like sensors that we attach to the baby’s scalp with adhesive. While the baby sleeps, we send clicking sounds through tiny earphones in the baby’s ears. This test measures hearing nerve activity in response to the sounds. It is painless and takes approximately two hours. We either do the test during natural sleep (called an unsedated ABR) or, if we don't expect the baby to sleep naturally for that long, a doctor prescribes a safe liquid sedative, and a nurse monitors your baby while we do the test. This is a sedated ABR.

Auditory steady state response (ASSR)

This is very similar to the ABR. It is also a sleeping hearing test that measures an electrical response of the inner ear and auditory nerve. For this test, we place small disk-shaped sensors behind each ear and on your baby’s forehead. We then present sounds to the ears using miniature earphones. We either do the test during natural sleep or with the use of a mild sedative, along with sleep-deprivation techniques. The main difference between ASSR and ABR is that ASSR is usually faster to show that hearing is normal, because we can test both ears at the same time, whereas with ABR, we must test each ear one at a time.

Visual reinforcement audiometry (VRA)

We usually do this hearing test for infants over six months of age. It takes advantage of the way a baby naturally turns its head  to look for the source of sounds. We teach your baby to turn to sounds by reinforcing the head-turn with toys that light up. We present sounds through little plugs that fit in the ear canal, through headphones and/or speakers.

Behavioural observation audiometry (BOA)

We use this test to observe hearing behaviour responses to sound when the head-turn test (VRA above) is not possible. We often need to do additional testing.

Acoustic immittance (also called tympanometry or impedance)

This test helps determine how the middle ear is functioning. Ear infections affect the middle ear. This test does not show whether the hearing is normal.

Toddlers

Hearing evaluation may include the tests mentioned above, along with the following:

Play audiometry

This test uses game-playing in response to sound. The toddler usually wears earphones. We ask the child to do something with a toy (touch or move it, for example) every time they hear the sound. This test relies on the cooperation of the child.

Auditory brainstem response testing under sedation

This is a sleeping hearing test. We use a mild sedative to get the child to sleep. We place small disk-like sensors on the scalp and put insert plugs in the toddler’s ears. While the child sleeps, we send clicking sounds through the plugs. This test measures hearing nerve activity in response to the sounds. It is painless and takes approximately two hours.

Older children

Hearing evaluation for a child older than three to four years may include the tests mentioned above along with the following:

Pure tone audiometry

This test uses sounds at different volumes and pitches with headphones over your child’s ears. In this age group, we simply ask the child to respond in some way when they hear the tone.