What is an auditory processing disorder?
Some persons have difficulty in listening situations but, according to standard audiologic tests, they have no evidence of hearing loss. They often complain of problems related to localizing sounds, listening in the presence of background noise, or clearly understanding words or combinations of words. In children, an APD often leads to classroom concerns, language/learning disabilities, and reading disorders. In adults, an APD interrupts healthy communication within families and in the workplace and can interfere with job performance.

How and by whom is an auditory processing disorder diagnosed?
Not all audiologists are trained to perform APD tests, but many are familiar with standard test protocols than can be used. The National Coalition on Auditory Processing Disorders (NCAPD) maintains a list of audiologists within each state who are available for consultation if you suspect an APD. The list is available on their website at www.ncapd.org . Most audiologists will combine results from a patient history, several checklists designed to assess where the problems most often occur, and a battery of screening and diagnostic tests to identify which area of auditory processing is causing the listener the greatest difficulty.

What types of diagnoses are made for APD?
There are several different profiles of APD that have emerged and it is possible that, with advances in research, audiologists will better identify the specific patterns of behavior that fit each of the profiles. For example, is it hardest when listening to speech in background noise? When trying to process competing information through the two ears, or when listening to slightly muffled speech as when listening on the telephone? These are just a few of the typical complaints that persons with APD might have and when test results correspond with reports of difficulty, the audiologist is better able to make a diagnostic identification of which profile the person best fits.

What can be done to help a person who has APD?
For many years persons with APD were told that they had the problem but there was little that could be done to help them. This is no longer true. There are many speech and language therapies that can prove effective in helping persons with APD, especially for children having difficult learning language in school. In addition, there is a variety of commercially available programs, many of which are computer-based, that have demonstrated benefits for both children and adults with APD. While there are no guarantees that any program will alleviate all of the difficulties with APD, there are reports of many gains made by listeners who have used these programs.

For persons whose primary difficulty occurs when listening in background noise, there are a number of assistive listening devices that can be used in those circumstances. In the past, most children with APD were given FM systems to use in school. When some of the children failed to show an improvement with the device, many schools lost confidence in the ability of an FM system to aid a child with APD. Today, the goal in fitting of an assistive listening device is to better identify which children might benefit from the use of one (and there are many who will) so that the schools and teachers will understand how dramatically they can assist some of the children with APD.

What is the most common finding in persons with APD?
All humans are slightly asymmetric. We have a stronger hand, a stronger eye and a stronger ear. For most, it is usually the right ear that dominates our auditory processing. This doesn't mean that the left ear is weak, but it means that the left ear doesn't perform at the same level as the right ear. Many children and adults with APD have a significantly larger difference between performance in the two ears than is seen in normal listeners. There is still a great deal to learn about these differenced, but some benefits have been found when training programs are focused on facilitating listening behavior in the weaker left ear. Listeners with larger than normal difference between the two ears are less likely to benefit from an assistive listening device (which serves only to make the differences louder). Training programs need to be developed that will train the ears to work more equally so that the degree of asymmetry can approach normal levels.

What about APD in a person who has hearing impairment?
Hearing loss often leads to processing problems. It can be very difficult to separate the effects of hearing loss from those that may be related to APD alone, but there are a few signs to watch for. If a listener has been wearing two hearing aids successfully and begins to notice that one hearing aid doesn't seem to be working effectively, this can be a sign of an APD. The hearing aid should be thoroughly checked first to be sure that it is working normally. If it is, then the listener should ask the audiologist to test for and APD to see if changes in the auditory system are interfering with benefits from the binaural hearing aids. In many listeners, a solution arrives with a change to wearing only one hearing aid for part of the time, especially when listening to conversations and other forms of speech as in watching TV, going to church, or attending a lecture.

What about ADD/ADHD and other problems that listeners may have?
Several problems can lead to similar listening difficulties. If the listener or the audiologist suspects that some other condition may be involved, there are other professionals who can be asked to participate in the overall testing to help determine what conditions are present. These might include a psychologist or neuropsychologist, a physical therapist, an occupational therapist or physician. The audiologist can help put together a team of professionals to make the best overall diagnosis.

This article was originally submitted by Deborah Moncrieff, Ph.D. and subsequently edited by AAC.