Auditory Processing Disorder (APD)
Auditory Processing Disorder (APD), also known as Central Auditory Processing Disorder (CAPD) is an umbrella term for a variety of disorders that affect the way the brain processes auditory information. Individuals with APD usually have normal structure and function of the outer, middle and inner ear (peripheral hearing). However, they cannot process the information they hear in the same way as others do, which leads to difficulties in recognizing and interpreting sounds, especially the sounds composing speech.
Diagnosing APD
Children with APD may exhibit a variety of listening and related complaints. For example, they may have difficulty understanding speech in noisy environments, following directions, and discriminating (or telling the difference between) similar-sounding speech sounds. Sometimes they may behave as if a hearing loss is present, often asking for repetition or clarification. In school, children with APD may have difficulty with spelling, reading, and understanding information presented verbally in the classroom. Often their performance in classes that don't rely heavily on listening is much better, and they typically are able to complete a task independently once they know what is expected of them. However, it is critical to understand that these same types of symptoms may be apparent in children who do not exhibit APD. Therefore, we should always keep in mind that not all language and learning problems are due to APD, and all cases of APD do not lead to language and learning problems. APD cannot be diagnosed from a symptoms checklist. No matter how many symptoms of APD a child may have, only careful and accurate diagnostics can determine the underlying cause.
A multidisciplinary team approach is critical to fully assess and understand the cluster of problems exhibited by children with APD. Thus, a teacher or educational diagnostician may shed light on academic difficulties; a psychologist may evaluate cognitive functioning in a variety of different areas; a speech-language pathologist may investigate written and oral language, speech, and related capabilities; and so forth. Some of these professionals may actually use test tools that incorporate the terms "auditory processing" or "auditory perception" in their evaluation, and may even suggest that a child exhibits an "auditory processing disorder." Yet it is important to know that, however valuable the information from the multidisciplinary team is in understanding the child's overall areas of strength and weakness, none of the test tools used by these professionals are diagnostic tools for APD, and the actual diagnosis of APD must be made by an audiologist.
To diagnose APD, the audiologist will administer a series of tests in a sound-treated room. These tests require listeners to attend to a variety of signals and to respond to them via repetition, pushing a button, or in some other way. Other tests that measure the auditory system's physiologic responses to sound may also be administered. Most of the tests of APD require that a child be at least 7 or 8 years of age because the variability in brain function is so marked in younger children that test interpretation may not be possible.
Once a diagnosis of APD is made, the nature of the disorder is determined. There are many types of auditory processing deficits and, because each child is an individual, APD may manifest itself in a variety of ways. Therefore, it is necessary to determine the type of auditory deficit a given child exhibits so that individualized management and treatment activities may be recommended that address his or her specific areas of difficulty.
Treating APD
It is important to understand that there is not one, sure-fire, cure-all method of treating APD. Notwithstanding anecdotal reports of "miracle cures" available in popular literature or on the internet, treatment of APD must be highly individualized and deficit-specific. No matter how successful a particular therapy approach may have been for another child, it does not mean that it will be effective for your child. Therefore, the key to appropriate treatment is accurate and careful diagnosis by an audiologist.
Treatment of APD generally focuses on three primary areas: changing the learning or communication environment, recruiting higher-order skills to help compensate for the disorder, and remediation of the auditory deficit itself. The primary purpose of environmental modifications is to improve access to auditorily presented information. Suggestions may include use of electronic devices that assist listening, teacher-oriented suggestions to improve delivery of information, and other methods of altering the learning environment so that the child with APD can focus his or her attention on the message.
Compensatory strategies usually consist of suggestions for assisting listeners in strengthening central resources (language, problem-solving, memory, attention, other cognitive skills) so that they can be used to help overcome the auditory disorder. In addition, many compensatory strategy approaches teach children with APD to take responsibility for their own listening success or failure and to be an active participant in daily listening activities through a variety of active listening and problem-solving techniques.
Finally, direct treatment of APD seeks to remediate the disorder, itself. There exist a wide variety of treatment activities to address specific auditory deficits. Some may be computer- assisted, others may include one-on-one training with a therapist. Sometimes home-based programs are appropriate whereas others may require children to attend therapy sessions in school or at a local clinic. Once again, it should be emphasized that there is no one treatment approach that is appropriate for all children with APD. The type, frequency, and intensity of therapy, like all aspects of APD intervention, should be highly individualized and programmed for the specific type of auditory disorder that is present.
Information provided by the American Speech Hearing Association www.asha.org
To find an audiologist in your area, contact the American Speech-Hearing Association at 1-800-638-8255
