Central Auditory Processing Disorders (CAPD)
Central Auditory Processing Disorders (or simply, auditory processing disorders) are problems with how the brain processes auditory information that comes from the ears. This processing involves many different skills; for example, attention to sound, ability to focus on speech and ignore background noise, discrimination of pitch, loudness, and other characteristics of sound, associating sounds with meaning, ability to break words down into component sounds or put sounds together into words, and so on.
The causes of CAPD are not known for sure. They may be due to differences in the way the brain develops. There is also some evidence that CAPD are related to causes such as head trauma, recurrent ear infections in early childhood, lead poisoning, oxygen deprivation, etc. Some conditions (e.g., autism, ADHD) may cause trouble with listening, understanding and remembering auditory information; however, the term CAPD refers only to auditory problems that are not caused by other cognitive or language problems or global conditions. They are also not caused by hearing loss.
Symptoms of CAPD
If CAPD are not detected and treated early, children with CAPD can develop language and speech delays, and may have trouble in school. Symptoms vary from mild to severe, and may include:
- Frequently asks for repetition or clarification
- Particular difficulty understanding speech in noisy settings
- Problems telling the difference between words that sound similar
- Difficulty following both simple and complicated directions
- Trouble following conversation on the phone
- Difficulty with reading, writing or spelling
- Lack of interest in music
- Difficulty learning foreign languages
Assessing and Treating CAPD
When an auditory processing disorder is suspected, a team of professionals will conduct testing to look at all aspects of the disorder. This team might include a teacher to look at academic issues, a psychologist to assess cognitive skills, and a speech-language pathologist (SLP) to test speech and language skills. However, only an audiologist (hearing specialist) can make the diagnosis of CAPD. He does this by performing a series of tests of hearing and the brain's response to auditory stimuli.
Treatment by the SLP or other professionals must be individualized and focused on the specific area(s) of difficulty. Therapy activities may include practice with a therapist, computer-based programs, or home exercises aimed at improving the impaired skills. The SLP may also train the client to use compensatory strategies that use areas of strength (visual skills, memory, etc.) to overcome the auditory issues. He may teach the client and/or family and teachers to modify the home or school environment in ways that make the auditory problems more manageable. Examples are: using an electronic device to assist listening; sitting at the front of the class; taking tests in a quiet room; or having the teacher provide visual information in addition to auditory.