A hearing exam tests a person’s ability to hear sounds. Hearing occurs when sound waves move through the nerves of the inner ear to the brain. Sounds vary according to the intensity (volume or loudness) and the pitch (speed of sound vibrations). Intensity of sound is measured in decibels (dB). Pitch of sound is measured in cycles per second (cps) or Hertz (Hz). A hearing exam is also called an audiogram or audiometry.
Why a hearing exam is done
A hearing exam may be done to:
- detect hearing problems
- monitor any effects of chemotherapy drugs on the hearing
- Hearing tests may be done before and after receiving chemotherapy.
How a hearing exam is done
There are many different types of tests that can be used to check a person’s hearing. Some of them may be used on people of all ages. Others are used based on the person’s age and level of understanding.
Hearing tests for newborns and infants
There are 3 main types of hearing tests for newborns and infants to about 6 months of age. They may be used alone or together.
Otoacoustic emissions (OAE) testing
This test is painless and is usually completed within a few minutes. The baby will sleep or lay quietly during the test.
- A tiny, flexible plug is inserted into the baby’s ear.
- Sounds are sent into the ear through the plug.
- A microphone in the plug records the responses, or otoacoustic emissions, of the ear in reaction to the sounds.
Auditory brainstem response (ABR)
The test is painless and can take less than 20 minutes, once the baby is asleep.
- Electrodes (wires) are attached to the baby’s scalp and earphones are placed in the baby’s ears.
- While the baby sleeps, sounds are made through the earphones.
- The test measures the brain’s activity in response to the sounds.
This test observes the behaviour of the infant in response to certain sounds. It must be used with ABR or EOAE to accurately determine the baby’s hearing status.
Hearing tests for toddlers
Hearing tests used for toddler include EOAE and ABR, as well as VRA and play audiometry.
Visual reinforcement audiometry (VRA)
This test is used most often for children between 6 months and 3 years of age.
- The child is trained to look toward a sound source when a sound is presented.
- When the child turns in response to a sound, the child is “rewarded” though a visual reinforcement, such as a toy that moves or a flashing light.
This test requires the child’s cooperation, so it is used with children 3–5 years of age.
- Sounds at different volumes and pitches are presented into the child’s ears, usually through headphones or earphones.
- The child is asked to do something with a toy (for example, drop a block in a bucket) every time the sound is heard.
Hearing tests for older children and adults
The following hearing tests are used for anyone older than 4 years of age.
Pure tone audiometry
- The audiologist presents sounds at different volumes and pitches into the person’s ears.
- The person usually wears some type of earphones.
- The person is simply asked to respond in some way (such as by raising a hand or pushing a button) each time the tone is heard in the earphone.
Speech reception and word recognition tests
- This test measures the ability to hear and understand normal conversation.
- The person repeats back words spoken with different degrees of loudness.
Tympanometry or impedance audiometry
This test is done to determine how the middle ear is functioning. It doesn’t test the person’s hearing, but helps to detect any changes in pressure in the middle ear.
- A soft plastic tip is placed over the ear canal.
- The machine measures eardrum movement when the pressure changes.
What happens if a change or abnormality is found
The doctor will decide whether further tests, procedures, follow-up care or additional treatment is needed.
Special considerations for children
Being prepared for a test or procedure can reduce anxiety, increase cooperation and help the child develop coping skills. Parents and caregivers can help prepare children by explaining to them what will happen, including what they will see, feel and hear during the test.
The preparation you can provide for this test depends on the age and experience of the child. See the following for more age-specific information on helping children cope with tests and treatment.