A hearing (audiometric) test is part of an ear
examination that evaluates a person's ability to hear by measuring the ability
of sound to reach the brain.
The sounds we hear start as
vibrations of air, fluid, and solid materials in our environment. The
vibrations produce sound waves, which vibrate at a certain speed (frequency)
and have a certain height (amplitude). The vibration speed of a sound wave
determines how high or low a sound is (pitch). The height of the sound wave
determines how loud the sound is (volume).
Hearing happens when
these sound waves travel through the ear and are turned into nerve impulses.
These nerve impulses are sent to the brain, which "hears" them.
Hearing tests help determine what kind of
hearing loss you have by measuring your ability to
hear sounds that reach the inner ear through the ear canal (air-conducted
sounds) and sounds transmitted through the skull (bone-conducted sounds).
Most hearing tests ask you to respond to a series of tones or
words. But there are some hearing tests that do not require a response.
Hearing tests may be done:
Tell your doctor if you:
Before beginning any hearing tests, the health professional
may check your ear canals for earwax and remove any hardened wax, which can
interfere with your ability to hear the tones or words during testing.
For tests in which you wear headphones, you will need to remove
eyeglasses, earrings, or hair clips that interfere with the placement of the
headphones. The health professional will press on each ear to find out whether
the pressure from the headphones on your outer ear will cause the ear canal to
close. If so, a thin plastic tube may be placed in the ear canal before the
testing to keep your ear canal open. The headphones are then placed on your
head and adjusted to fit.
If you are wearing hearing aids, you
may be asked to remove them for some of the tests. You may be asked to shampoo
your hair before you have auditory brain stem response (ABR) testing.
Talk to your doctor about any concerns you have about the need for a
hearing test, its risks, how it will be done, or what the results will mean. To
help you understand the importance of this test, fill out the
medical test information form(What is a PDF document?).
Hearing tests can be done in an
audiometry laboratory by a hearing specialist (audiologist) or in a doctor's office, a school, or the workplace by a nurse, health
professional, psychologist, speech therapist, or audiometric technician.
In a whispered speech test,
the health professional will ask you to cover the opening of one ear with your
finger. The health professional will stand
1 ft (0.3 m) to
2 ft (0.6 m) behind you and
whisper a series of words. You will repeat the words that you hear. If you
cannot hear the words at a soft whisper, the health professional will keep
saying the words more loudly until you can hear them. Each ear is tested
Pure tone audiometry uses a
machine called an audiometer to play a series of tones through headphones. The
tones vary in pitch (frequency, measured in hertz) and loudness (intensity,
measured in decibels). The health professional will control the volume of a
tone and reduce its loudness until you can no longer hear it. Then the tone
will get louder until you can hear it again. You signal by raising your hand or
pressing a button every time you hear a tone, even if the tone you hear is very
faint. The health professional will then repeat the test several times, using a
higher-pitched tone each time. Each ear is tested separately. The headphones
will then be removed, and a special vibrating device will be placed on the bone
behind your ear. Again, you will signal each time you hear a tone.
A tuning fork is a metal,
two-pronged device that produces a tone when it vibrates. The health
professional strikes the tuning fork to make it vibrate and produce a tone.
These tests assess how well sound moves through your ear. Sometimes the tuning
fork will be placed on your head or behind your ear. Depending on how you hear
the sound, your health professional can tell if there is a problem with the
nerves themselves or with sound getting to nerves.
reception and word recognition tests measure your ability to hear and
understand normal conversation. In these tests, you are asked to repeat a
series of simple words spoken with different degrees of loudness. A test called
the spondee threshold test determines the level at which you can repeat at
least half of a list of familiar two-syllable words (spondees).
emissions (OAE) testing is often used to screen newborns for hearing problems.
In this test, a small, soft microphone is placed in the baby's ear canal. Sound
is then introduced through a small flexible probe inserted in the baby's ear.
The microphone detects the inner's ear's response to the sound. This test
cannot distinguish between conductive and sensorineural hearing loss.
Auditory brain stem response (ABR) testing detects sensorineural hearing
loss. In this test, electrodes are placed on your scalp and on each earlobe.
Clicking noises are then sent through earphones. The electrodes monitor your
brain's response to the clicking noises and record the response on a graph.
This test is also called brain stem auditory evoked response (BAER) testing or
auditory brain stem evoked potential (ABEP) testing.
There is normally no discomfort involved
with a hearing test.
There are no risks associated with hearing
A hearing test is part of an ear
examination that evaluates a person's ability to hear.
Sound is described in terms of
frequency and intensity. Your hearing threshold is how loud the sound of a
certain frequency must be for you to hear it.
The following table relates how loud a sound must be for a
person to hear it (hearing thresholds) to the degree of hearing loss for
Difficulty with faint or
Difficulty with conversational
Speech must be loud;
difficulty with group conversation
Difficulty with loud speech;
understands only shouted or amplified speech
May not understand amplified
Reasons you may not be able to
have the test or why the results may not be helpful include:
CitationsU.S. Preventive Services Task Force (2008). Universal
screening for hearing loss in newborns: U.S. Preventive Services Task Force
Recommendation Statement. Pediatrics, 122(1): 143–148.
Also available online:
http://www.uspreventiveservicestaskforce.org/uspstf/uspsnbhr.htm.Other Works ConsultedAmerican Academy of Pediatrics (2008). Recommendations
for preventive pediatric health care. In Bright Futures: Guidelines for Health Supervision of Infants, Children, and Adolescents,
3rd ed., p. 591. Elk Grove Village, IL: American Academy of Pediatrics. Also
October 25, 2011
Sarah Marshall, MD - Family Medicine & Steven T. Kmucha, MD - Otolaryngology
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