The first step in diagnosing hearing loss is to undergo a hearing evaluation. A comprehensive evaluation consists of a series of individual tests that will help determine the extent and type of hearing loss. Our audiologists at Southern Utah Ear, Nose, Throat, Allergy, and Facial Plastics are skilled in conducting a number of tests to help diagnose and treat patients with hearing loss. Not all patients who experience hearing loss are aware of their condition. Symptoms tend to develop gradually over an extended period of time. Hearing tests may help detect a problem early, improving the chances of successful treatment.
Even individuals who do not suspect hearing loss should consider regular hearing tests once they reach the age of 50. And they’re not just for older adults; babies and toddlers should have their hearing tested in order to prevent delays in speech and language development should a hearing impairment exist.
Hearing tests are completely safe and painless. They are performed in a soundproof booth and results are plotted on a graph that shows the patient’s hearing response at different frequencies. This is called an audiogram, and will help the audiologist determine the best way to treat the hearing loss.
Types of Hearing Tests
A typical hearing evaluation is comprised of a number of separate hearing tests.
Pure-tone testing (also known as pure tone audiometry) uses air conduction to measure a patient’s ability to hear sounds of various pitches and volumes. They are given headphones to wear and asked to identify a series of tones by raising a hand, pressing a button or responding verbally. The results are charted on an audiogram, a graph that shows the type, degree and configuration of the hearing loss by comparing pitch (frequency) with loudness (intensity). The pattern recorded will help the audiologist determine the individual’s hearing threshold.
Bone Conduction Testing
Bone conduction testing is another type of pure-tone test that measures the inner ear’s response to sound. In this case, a two-pronged metal tuning fork is placed behind the ear or on the forehead. When vibrated, it produces a tone that travels to the cochlea via the skull. The patient’s response determines how well sound travels through different parts of their ear, helping the audiologist diagnose the type of hearing loss. Bone conduction testing is often used in place of air conduction testing when an obstruction in the outer or middle ears is present.
Speech (or word recognition) testing is used to measure the speech reception threshold (SRT), or the faintest speech the patient can understand 50 percent of the time. This is compared with their pure-tone test results to confirm the diagnosis. In addition, the ability to separate speech from background noise will be recorded. Speech testing may be administered in either a quiet or noisy environment; results are recorded on the audiogram for easy visual reference.
Tympanometry is a test of the middle ear used to detect fluid, wax buildup, eardrum perforations and tumors. It measures movement of the eardrum in response to air pressure; the results are recorded on a chart called a tympanogram.
Acoustic Reflex Test
The acoustic reflex test measures involuntary muscle contractions of the middle ear, and is used to determine the location of the hearing problem (the ossicles, cochlea, auditory nerve, etc.) as well as the type of hearing loss.
Auditory Brainstem Response (ABR)
Auditory brainstem response (ABR) testing is used to determine whether a specific type of hearing loss – sensorineural – exists. It is also frequently used to screen newborns for hearing problems. In an ABR test, electrodes are attached to the patient’s head, scalp or earlobes and they are given headphones to wear. Their brainwave activity is measured in response to sounds of varying intensities.
Otoacoustic Emissions (OAEs)
Otoacoustic emissions (OAEs) are sounds generated by vibrations of the hair cells in the cochlea of the inner ear. OAE testing utilizes a tiny probe fitted with a microphone and speaker that is used to stimulate the cochlea and measure its response. Individuals with normal hearing will produce emissions; when a hearing loss exceeds 25-30 decibels, no sound will be produced. This helps determine whether there is a blockage in the ear canal, excess fluid in the middle ear or damage to the hair cells of the cochlea. OAE testing is often included in newborn hearing screening programs.
Call Southern Utah Ear, Nose, Throat, Allergy, and Facial Plastics at (435) 628-3334 for more information or to schedule an appointment.