What is Audiometry?

Types of Audiometry Tests

Pure-Tone Audiometry

The most common audiometry test is pure-tone audiometry. In this test, a person wears headphones and listens to various pitches at different volumes to determine their hearing levels. The test delivers sounds from 250 to 8000 Hz (hertz), and the levels are reduced to the softest sound a patient can hear 50 percent of the time. This establishes the hearing threshold to indicate hearing loss.

Speech Audiometry

A step beyond pure-tone audiometry, speech audiometry measures how a person hears and understands spoken words. Instead of tones, this test plays words at various volumes. This shows how loud a word has to be for the person to understand it, as well as how clearly they can understand speech.

Bone conduction

Instead of regular headphones, bone conduction audiometry uses a bone oscillator. This device is placed behind the ear and vibrates to send sound directly to the cochlea. When this occurs, the person indicates when they can hear tones until they can’t anymore. This test measures how well sound can travel to the inner ear, skipping any wax, fluid, or other pathology in the outer and middle ear.

Tympanometry

Also known as impedance audiometry, tympanometry tests the middle ear and eardrum. This test changes the pressure of the middle ear to see how well it transmits sound at varying levels. Tympanometry can help diagnose middle ear fluid build up or a torn eardrum.

Otoacoustic Emissions (OAEs)

Otoacoustic emissions audiometry is done mainly on infants, young children, and those who cannot participate in other hearing tests. Instead of having the patient respond to sound, a small microphone and speaker are inserted into the ear.

The speaker plays small sounds, and the microphone picks up any echo created by the hair cells in the cochlea. If the inner ear is working correctly, the echoes will be strong.

Auditory Brainstem Response (ABR)

Like OAEs, auditory brainstem response audiometry testing is usually done on infants, young children, and those who cannot participate in traditional hearing tests. This test measures how nerves and the brain respond to sound. That is measured by electrodes placed around the ears and head. As headphones transmit sound, the electrodes measure the auditory nerve’s response.

What to Expect During an Audiometry Test

Since there are many types of audiometry tests, it can be hard to say exactly what to expect. But most likely, you’ll wear headphones in a quiet room and respond to sounds by pressing a response button or raising your hand. The test will likely be done by an audiologist or hearing care professional.

How to Prepare for the Audiometry Test

Generally, you don’t need to do anything to prepare for a hearing test. But there are some things to consider before your appointment.

• Avoid loud noises: For at least 24 hours before your test, avoid loud noises that could temporarily impact your hearing.
• Clean your ears: This does not mean putting cotton swabs in your ears. All you need to do is clean the outer part of your ear with a damp washcloth to remove skin or wax buildup. It is never a good idea to put anything inside your ear.
• Get some sleep: It’s best to do a hearing test after a good night’s sleep so you’re alert and can concentrate on the test.
• Reschedule if you’re sick: Being sick can impact your hearing. It’s best to do a test when you’re feeling better unless you’re getting a hearing test to diagnose ear infections or middle ear fluid.

Interpreting Audiometry Results

The Audiogram

An audiogram is the result of an audiometry test. It is shown as a graph with pitch on one axis and volume on the other. Audiograms will show how loud a pitch has to be for the person to hear it.

These results demonstrate whether someone has hearing loss and at what level. They can also be repeated to show whether the hearing loss is progressing.

Hearing Loss Categories

There are three types of hearing loss:

• Conductive hearing loss: Hearing loss occurs because sound cannot reach the inner ear. Sounds are not being transmitted properly through the outer and/or middle ear.
• Sensorineural hearing loss: Either the inner ear or the auditory nerve is damaged. Because of this, the brain cannot process the sounds.
• Mixed hearing loss: There are issues with getting sound to the inner ear and the inner ear itself, which can’t transmit sound properly to the brain.

Beyond the type of hearing loss, there are also different severities. Each severity explains how much a person can hear with their hearing loss.

• Mild (26-60 dB): The least amount of hearing loss. A person with mild hearing loss may have trouble hearing quiet sounds like a whisper.
• Moderate (41-55 dB): At this level of hearing loss, it becomes harder to understand conversations at a normal volume.
• Moderately Severe (56-70dB): Without hearing aids, it becomes very difficult to hear other people talking at a regular volume, understand speech on TV or in groups.
• Severe (71-90dB): Clarity sounds of speech are inaudible at this level of hearing loss without a cochlear implant or hearing aids. Without them, an individual may only be able to hear loud sounds.
• Profound (91+ dB): Even very loud sounds like sirens may be difficult to hear. Hearing aids will do little to help with this level of hearing loss.

What happens if my results show hearing loss?

If your audiometry test indicates hearing loss, you can create a treatment plan with an audiologist or hearing specialist. Depending on the level of hearing loss, you may want to get hearing aids or surgical intervention. You may also be able to further protect your hearing by implementing lifestyle changes like wearing ear protection at work.

Who Should Get an Audiometry Test?

First and foremost, if you are experiencing hearing loss, you should get an audiometry test. Having them as part of their routine exams is also good for children. People over the age of 50 or who have a family history of hearing loss should also get routine audiometry tests, as well as anyone who is frequently exposed to loud noise.

Recent Advances in Audiometry Technology

Thanks to advances in technology, audiometry is more accessible than ever. Some audiologists can do home visits using portable audiometry devices.

And with automated audiometry online tools, people can do a basic hearing test from home before going to a doctor. While that doesn’t give an official diagnosis, it may provide some idea of whether they are having hearing loss.

Conclusion

Early detection of hearing loss is one reason why audiometry is so important. These tests allow people to track their hearing loss progression to help accommodate issues as they happen. This also means a better quality of life for impacted individuals since they can stay on top of their hearing health.