Diagnostic Audiologic Evaluations
If you or your child has been referred for a diagnostic audiologic evaluation, it means that hearing loss needs to be ruled out or further examined. The diagnostic audiologic evaluation may be indicated for individuals who did not pass an initial hearing screening.
The evaluation is done to determine if a hearing loss is present, and if so, to detail the type and severity of the hearing loss. It also may provide insight in to the cause of the hearing loss as well as provide guidance for the audiologist in making appropriate treatment recommendations.
The audiologist will perform otoscopy, i.e., examining the ear canal. This is done to ensure there are no medical issues to impede testing (e.g., wax). A referral to an ear, nose, throat physician my be recommended prior to testing.
What Tests Will Be Done?
The specific tests done during the evaluation will depend on the patient's age, and what is known already about their hearing status. These various tests will tell the degree of hearing loss, the type of hearing loss, and the conditions of the ear canal and middle ear. The audiologist will also determine if the hearing loss is conductive (middle or outer ear problem) or sensorineural (inner ear problem or central processing difficulty of the brain).
A diagnostic audiologic evaluation includes pure-tone testing, bone-conduction testing, and speech testing.
Pure-tone Air and Bone Conduction Testing
Pure-tone air conduction testing determines the quietest tones that a person can hear at different frequencies, both low and high. Bone conduction testing is similar to pure-tone air conduction testing. A different type of headphone is used during bone conduction testing, and the results help the specialist determine if the hearing loss is originating from the outer/middle ear or from the inner ear.
A speech reception threshold (SRT) test is often used with older children and adults to confirm the results of a pure-tone test. This test determines the lowest level at which the patient can recognize words or speech stimuli.
Speech testing also includes word recognition score (WRS). This is performed to determine optimum performance word recognition under standardized conditions.
Specialized tests exist for infants and young children, as well as children and adults with developmental and cognitive impairments. These more-specialized tests allow the audiologist to test the auditory system when the patient is not able to actively participate in the tests or evaluation.
Other tests may include:
Tympanometry: Tympanometry may be performed to assist in diagnosing and monitoring problems with the middle ear and ear canal.
Otoacoustic Emissions Testing: The primary purpose of otoacoustic emissions testing (OAE's) is to determine hair cell function in the cochlea. It is a valuable tool for screening infants and testing children in that it will estimate hearing sensitivity within a limited range. No behavioral response is required by the patient. The test is also performed on adults.
Along with the evaluation, you should generally expect to have time to review the results with the audiologist. He or she can interpret the tests for you, answer your questions, provide you with information and referrals as needed, as well as begin planning for treatment, if indicated.
Audiologists are specialists in hearing and hearing rehabilitation. Never hesitate to ask your audiologist for clarification or further information on anything you do not understand.