Understanding and diagnosing hearing loss
T
he ears are sensitive sensory organs of the body that are susceptible to damage, including hearing impairment or loss. The National Institute on Deafness and Other Communication Disorders says approximately 15 percent of the United States population between the ages of 20 and 69 has high frequency hearing loss due to exposure to loud sounds or noise from work and leisure activities. School-aged children and even babies can have varying stages of hearing loss. Such loss might have been present at birth, but it also can be a byproduct of environmental factors. Statistics Canada reports more than one million adults across Canada have a hearing-related disability. Types of hearing loss Any person can experience hearing loss and at varying degrees. Medical professionals distinguish different levels of hearing loss as mild, moderate, severe, and profound. The deafness can be categorized in two
main types:conductive and sensoryneural. If sound is blocked from reaching the inner ear in some way, then that person is said to have conductive hearing loss. If the problem stems from impairment of sensory cells inside of the ear or neurological impairment that compromises reception of sound or understanding of language, the person is said to have sensory-neural hearing loss. Hearing loss testing Tests will determine the type and the severity of hearing loss. Hearing tests may be part of routine examinations performed by pediatricians as children age. But once people reach adulthood, hearing tests are not common unless they are requested in response to a specific medical issue. The American Hearing Research Foundation identifies six types of hearing tests. * Bedside testing: Doctors can use screening procedures to identify symptoms of hearing loss. A doctor may use some sort of common sound,
such as whispering, snapping or a ticking watch, to quantify a patient’s ability to hear sounds. He or she also may use tuning forks to test at chosen frequencies. The Rinne test is a common tuning fork test that identifies hearing discrepancies when the tuning fork is placed on the mastoid bone and then one inch from the external ear canal. Audiometry: This test is conducted using an audiometer that gives off a variety of pitches. When higher levels of decibels are needed, this indicates hearing impairment. The source of the hearing loss then needs to be identified. Tympanometry: This is a measure of the stiffness of the eardrum to evaluate middle ear function. Tympanometry can identify fluid in the middle ear, perforations and abnormal middle ear pressure. Brainstem auditory evoked responses: This test, often referred to as a BAER test, measures the timing of electrical waves from the brainstem in response to clicks sounded at the ear. Both ears are tested and then delays in one side to the other may be indicative of a problem. Electrocochleography: This test is a variant of the BAER and uses an electrode placed on or in the ear drum to amplify sound waves. Otoacoustic emission: This is a relatively new procedure used to assess hearing loss in newborns and also verify if the cochlea, which is the spiral-shaped hearing organ inside of the inner ear, is working correctly. A small probe is inserted into the ear, and quiet tones are sent to simulate movement of the hairs on the cochlea.
Should these hairs move, a tiny microphone will record the hairs’ own sounds and produce a response that indicates the cochlea is working. Identifying hearing loss Tests are only functional if hearing loss is identified and people take steps to confirm diagnosis. Often it is up to parents, spouses and caregivers to recognize the signs of hearing loss and suggest testing. Some signs of hearing loss are more noticeable than others. Here are some indicators. * Asking people to repeat themselves * Turning up the radio or television volume to a level that is loud for others * Difficulty hearing on a telephone * Difficulty hearing when women or children speak * Problems following a fast-moving conversation * Feeling like others are always mumbling * Difficulty making out conversations in noisy places If you have repeatedly experienced any of these signs, the American Speech-Language-Hearing Association suggests scheduling an appointment with your doctor. He or she can determine if an appointment with a certified audiologist is necessary. Although there is a strong relationship between age and hearing loss, anyone can experience hearing impairment. Being informed and seeking treatment can help improve hearing and communication in affected individuals.