Hearing loss is a big problem: approximately 466 million people worldwide suffer from some forms of hearing loss. That’s five percent of the world’s population. Approximately 40 million American adults experience some form of hearing loss. If you are experiencing symptoms such as difficulty understanding speech, having to ask others to repeat themselves, needing to constantly increase the TV or radio volume, or a ringing in your ears, then you may have hearing loss.
If so, then you should seek help. Your doctor may refer you to a licensed audiologist or other hearing health care professional who will administer a hearing test.
A hearing test is used to determine whether or not you have a hearing issue, and if you do, the severity of the problem. There are several types of hearing tests, and the type you receive will depend on the hearing problems that you are experiencing.
Pure Tone Testing
Pure tone testing is the test that you probably remember receiving in grade school, where you wear a pair of headphones, sit in a sound-isolating booth, and raise your hand or say “yes” whenever you hear a beep. This test is referred to as an air conduction test, because sound is passed through the air into your ears. This test is designed to find the lowest volume of sound that you can hear at different frequencies.
The audiologist changes the pitch and volumes of the tones throughout the test. Each ear is tested one at a time. The results of your pure tone test are recorded by the audiologist in what’s known as an audiogram.
Bone Conduction Testing
Contrary to the air conduction test described above, bone conduction testing measures how the inner ear responds to sounds via bone conduction. A conductor is placed behind the ear that transmits vibrations through the bone to the inner ear. The results of this type of test are usually compared to air conduction test to determine the type of hearing loss that a person is experiencing.
Speech testing examines how well you can hear and repeat words, measured by the speech reception threshold. In speech testing, you wear a pair of headphones into which the audiologist says words at certain volumes, and you repeat the words. The words are spoken at different volumes to determine the lowest volume of speech that you can recognize and repeat 50 percent of the time; this volume is the speech reception threshold. The test is often performed in a noisy environment because that’s the type of situation in which most people with hearing loss have the greatest difficulties.
A tympanometry test is designed to determine if there are issues with your eardrum, such as an ear infection, fluid or earwax buildup, or a rupture in the eardrum. A small probe is placed into each ear; these probes are attached to a device that pushes air into the ear in order to move the eardrum. The movement of your eardrum is recorded on a tympanogram. From the tympanogram, an audiologist can determine if your eardrum moves normally or has a problem indicated by stiff movement or too much movement.
Acoustic Reflex Testing
This type of hearing test is designed to measure involuntary muscle contractions in your inner ear and to find the location of any problems. Under normal circumstances, a small muscle inside your inner ear tightens when exposed to loud noises. This acoustic reflex is automatic and occurs without you even knowing it. In people with severe hearing loss, the sound may have to be very loud in order to elicit a response, or a response may not occur at all.
Auditory Brainstem Response
This type of hearing test is usually reserved for children or adults who cannot be tested with another type of test, or if the hearing loss is suspected to be related to problems in the brain. This test examines the cochlea and the brain pathways for hearing. For this type of test, electrodes are placed on your head which are connected to a computer. Brain wave activity is recorded in response to a series of sounds of different volumes heard through headphones.
The results are seen on a computer printout. No participation is required by the person testing; they can rest quietly or even sleep. For this reason, the auditory brainstem response test is often used with babies to examine potential hearing problems.
When sound waves enter your ear, the vibrations pass through your eardrum into the inner ear. There, the hair cells in the cochlea vibrate. These vibrations produce sound of their own which is transmitted back into the middle ear. These sounds are called otoacoustic emissions and this test measures those emissions.
People with normal hearing produce otoacoustic emissions which can be measured. However, people with hearing loss that is greater than 25-30 decibels do not produce these sounds. To perform the test, a small probe is placed in the ear. The probe contains a tiny speaker and microphone. The speaker plays clicks or tones which travel into the middle ear and into the cochlea.
The hair cells vibrate in response and the sound of that vibration travels back into the middle ear and ear canal where it is picked up by the microphone of the probe. The test determines whether or not the hair cells are functioning as they should.
The information in this guide has been written using the following reliable sources: