Hearing Loss
Diagnosis

Although hearing loss is very common among adults, particularly those over age 65, the condition is often under diagnosed in older people. Hearing loss can greatly impact a person's quality of life. Therefore, if hearing loss is suspected, it is important that the advice of a doctor specializing in diseases and conditions of the ear, known as an otologist, otolaryngologist, or ear, nose and throat doctor, is sought in order to make a definite medical diagnosis. The ear specialist also will work in close cooperation with audiologists, specialists in hearing disorders.

There are a variety of tests available to accurately diagnose the type and severity of hearing loss. These include:

• Air Conduction, Conventional or Standard Audiometry This test is commonly used to measure the hearing of adults and older children. A range of test tones, from low to high frequency (perceived as "pitch"), is transmitted through earphones placed on or in each ear, and patients are asked to indicate with a hand raise, button push or verbal response when you hear each sound. This testing determines the very softest signals you can hear at each of the presented frequencies, and indicates frequency regions in which hearing may be impaired. The louder the sounds must be made to be heard, the greater the degree of hearing loss at that particular frequency or frequencies. The frequencies tested are those important for hearing and understanding speech and other environmental sounds.
• Bone Conduction If testing reveals a hearing loss, another type of headset, a bone vibrator, is used to determine hearing by bone conduction in order to determine the type of hearing loss. This device sends sounds directly to the inner ear, bypassing the outer and middle ear. If the sounds are heard better by bone conduction, the hearing loss is conductive in nature and is likely located in the outer or middle ear. If the sounds are heard equally well with the earphones and the bone vibrator, the hearing loss is sensorineural in nature. A combination of conductive and sensorineural hearing loss also may be present; this is called a mixed hearing loss.
• Word Recognition In addition to tests with tones, word recognition testing is usually performed to evaluate the ability to discriminate differences between the speech sounds of various words, and how clearly the words are heard. During this test, you will be asked to listen to and repeat words.
• Acoustic Immittance These tests are used to assess the status of the middle ear and related structures. A type of acoustic immittance test called, tympanometry, measures the movement of the eardrum to see if it moves normally when pressure changes are applied. Restricted eardrum movement could indicate a problem with the eardrum or middle ear structures. Acoustic reflex testing, a method of determining how the middle ear reacts to loud sounds also might be tested.
• Otoacoustic Emissions (OAEs) OAEs are used to assess the function of the cochlea. OAEs are typically present when hearing is normal or near normal, and are typically absent when there is a problem in the cochlea.
• Auditory Brainstem Response (ABR) ABR is a procedure used to measure hearing sensitivity and determine if the neural pathways within the brainstem are transmitting sound properly. This test is used to rule out auditory-neurological problems. Brainwave activity in the auditory centers of the brain is recorded in response to a series of clicks or tones presented to each ear. During this procedure, electrodes are placed on the head to detect the electrical response of the brains to sounds presented while you rest or sleep. The electrodes do not cause pain or discomfort.