Special tests to determine hearing loss in children

bangalore: vikram, just two years old, was referred to audiologist dr sathya ranna. his mother told the doctor that despite being an intelligent child, he would not respond to calls. not even to noise-making toys, the doorbell or the loud mixie. says dr ranna, who works with the shreya hearing clinic, "improved technology helps identify permanent hearing loss soon after birth.however, regardless of age, a child with sensorineural hearing loss (a hearing problem in the inner ear) should be evaluated by an audiologist to determine which type of hearing aid may benefit him the most." "children who have normal hearing begin using single words at about one year of age. in reality, a great deal of language is learned before children utter their first word. hearing loss can disrupt language development because learning spoken language depends on the ability to hear speech." the ability to learn language peaks between two and four years of age. "for this reason, the earlier the findings of vikram's problems are made and corrective action taken, the greater are the chances of the boy developing listening abilities and using spoken language," dr ranna explains. before hearing aids can be purchased for vikram, the degree of hearing loss is determined. this is usually done using special test methods for infants, toddlers and young children. for vikram, the auditory brainstem response test (apr) was used. electrodes were placed on the child's scalp using an adhesive, then as the boy slept, sounds were played through earphones. responses to sounds were used to determine the degree of hearing loss. "after six months of age, infants, toddlers and older children may be tested with game like activities such as visual reinforcement audiometry (vra) or conditioned play audiometry (cpa). in this kind of testing children respond to a number different high or low pitch sounds, as well as to speech. the softest levels at which a response is observed indicate how much hearing loss is present. for these, a child's response to sounds are observed by the audiologists," dr ranna says. after determining the degree of hearing loss and receiving medical clearance to use hearing aids, the process of hearing aid evaluation begins. there are several techniques to do this. regardless of the technique used, the goal of amplifications is to enable conversational speech to be heard at a comfortable level. "we use mathematics to compute values for the hearing aid response based on the amount of hearing loss present so the performance of different hearing aids can be compared with the calculated targets," dr ranna says. another method of evaluating hearing aids for vikram was probe-microphone testing or real ear measurements. in this test, a tiny microphone is placed in the ear canal next to the earmold to measure the performance of a hearing aid in the ear. dr ranna adds safety is the overriding concern for the choice of behind the ear (bte) verus pocket hearing aids for children. bte hearing aids can be used with earmolds made of soft material as a safety precaution with physically active children. parents play an important role in this process of evaluating and using hearing aid amplification. they provide valuable information about a child's response and are critical to their child's successful use of hearing aids. (more details can be had from dr sathya ranna on 5273311).