Central auditory processing disorder, or CAPD, is a disorder within the central auditory nervous system that results in difficulties processing acoustic stimuli. In more simple terms, CAPD occurs when the brain does not process auditory information correctly. These hearing and listening difficulties are not related to higher-order, more global conditions. Patients who have CAPD may have a variety of auditory complaints; however, their hearing test will show normal hearing sensitivity.
Symptoms may range from mild to severe and include difficulty with any of the following:
- Hearing in noisy environments
- Following conversations
- Following directions
- Reading and spelling
- Mishearing or misinterpreting spoken information
Before an audiologist can further evaluate the presence of a CAPD, a routine hearing test must be completed first. During a routine hearing test, audiologists evaluate the peripheral auditory system (outer ear, middle ear, inner ear and the auditory nerve). If no peripheral hearing loss is present but the patient has auditory complaints, they may be referred on for further testing of auditory processing abilities, depending on their specific auditory complaints and medical history.
Before being scheduled for further evaluation of auditory processing, patients will be screened to rule out higher-order deficits that might contribute to listening difficulties, such as ADHD, intellectual disabilities and memory or executive function deficits.
Central auditory processing evaluations test beyond the peripheral auditory system. The evaluation includes specialized behavioral audiologic tests that evaluate different auditory processes. In some cases, elecrophysiologic tests are warranted in addition to behavioral testing. CAPD is diagnosed when patients score outside the normal range for their age on multiple tests and when there is a pattern to these deficits.
Treatment for CAPD can help patients with hearing and listening difficulties. Recommendations will be specific to the patient’s auditory processing deficits, but may include environmental changes, compensatory strategies and direct remediation.