An audiometry exam tests how well a person’s hearing functions. The test covers both intensity and tone of sounds to determine how well a person can hear. It is used to diagnose hearing loss.
The test is administered by an audiologist—a doctor who specializes in hearing loss, balance issues, and other issues related to the function of the inner ear.
A healthy human ear can hear quiet sounds like a whisper or a ticking clock. An audiometry test determines at what level of intensity and tone a person hears.
Sound intensity is measured in decibels (dB). For example, a human whisper is about 20 dB, while a jet engine is between 140 and180 dBs. A sound’s tone is measured in cycles per second in Hertz (Hz). Low bass tones measure around 50 Hz. Humans can hear tones between 20 and 20,000 Hz. Human speech generally falls in the 500 to 3,000 Hz range.
An audiometry test is performed to determine how well a person hears. This may be part of a routine screening or in response to a noticeable hearing loss.
Common causes of hearing loss include:
- birth defects
- chronic ear infections
- inherited conditions, such as otosclerosis where an abnormal growth of bone prevents structures within the ear from functioning properly
- injury to the ear
- inner ear diseases, such as Ménière’s disease or an autoimmune inner ear disease
- regular exposure to loud noises
- ruptured eardrum
Sounds louder than 85 dB—such as a rock concert—can cause hearing loss after a few hours. A good precautionary measure is to use hearing protection (such as foam ear plugs) if you are regularly exposed to loud music or industrial noise.
Audiometry is noninvasive and carries no risk.
An audiometry exam requires no special preparation. All you have to do is show up to your appointment on time and follow the audiologist’s instructions.
Audiometry involves using an audiometer, a machine that plays sounds via headphones. The audiologist or an assistant will play a variety of sounds, such as tones and speech, at different intervals into one ear at a time.
The audiologist will give you instructions for each sound. For instance, he or she may ask that you raise your hand when a sound becomes audible. This helps to determine the minimum intensity or the lowest volume that you can hear.
A tuning fork (a vibrating fork) may be used to determine how well a person hears vibrations through the ear. The doctor may put this metal device against the bone behind the ear (mastoid) or use a bone oscillator to determine how well vibrations pass through the bone to the inner ear. A bone oscillator is a mechanical device that transmits vibrations similar to a tuning fork.
The test causes no pain or discomfort and takes about an hour.
After your test, your audiologist will review your results with you. Depending on how well you hear volume and tone, your doctor will tell you about any preventative measures—such as wearing earplugs around loud noises—or corrective measures—such as wearing a hearing aid—that are required.