When our ear hears a sound, the sound is taken into the inner ear and delivered to the brain and the brain translates what is being heard. When a person is deaf, the part of the ear that delivers the sound to the brain does not function.
When a person has central auditory processing disorder (CAPD), the part of the brain that translates what the ear delivers does not function properly. The person with CAPD can hear sounds, but how the brain translates those sound is disrupted, and the end result is a garbled message.
People who have CAPD have normal hearing, so they are not considered hearing impaired. The neurological processing of the sounds they hear is impaired, which is why it's called a processing disorder.
Symptoms of CAPD
Most common symptoms include:
- Difficulty hearing in the presence of ambient noise
- Difficulty following along or keeping up in conversations
- Poor auditory memory
- Difficulty following auditory instructions, especially multi-step instructions
- Speech delay from a young age
- Often misinterprets what is said, but doesn't realize it's been misinterpreted
- Missed subtle social cues
- May have difficulty with phonics and learning to read
- Exhibits attention issues
- May exhibit auditory distractibility
- Often says "huh?" or "what?"
Subtypes of CAPD
Central Auditory Processing Disorder is a broad descriptor of issues related to various areas of auditory processing dysfunction. The subtypes describe specific areas of dysfunction so that specific remedies can be implemented. A person could have one or more of these subtypes.
- AUDITORY DECODING: Presents with auditory discrimination difficulties, especially in the presence of ambient sound. They have challenges analyzing differences between sounds. Challenged to hear rapid speech and often asks "huh?". Behaves as if there is a hearing loss when there is none. This is the classic type of CAPD.
- INTEGRATION: This sub-type demonstrates difficulties in tasks that require both sides of the brain to work together. Presents with reading challenges, reading comprehension, note-taking difficulties as well as physical coordination issues. May also have poor visual-motor abilities.
- ASSOCIATIVE: Presents with receptive language difficulties, especially with regards to the meaning of speech (semantics). Sometimes called a receptive language disorder. May have difficulty understanding common expressions that aren't literal (i.e. Aren't you just beat?).
- OUTPUT-ORGANIZATION: Difficulty with organizing language and difficulty with expressive language. Presents difficulty with recalling information in a specific order and may have articulation issues.
- PROSODIC: Presents as challenge with the prosodic elements of speech: tone, pitch, intonation. Listener cannot understand the underlying meaning behind the words that are said. May include poor pragmatic language skills and social challenges.
Visit website for Jeanne M. Ferre, PhD for detailed explanation of CAPD Subtypes.
CAPD vs. APD
Auditory Processing Disorder is a descriptive term that describes any issues related to the auditory system. This could include outer, middle and inner problems, as well as neurologic issues related to getting the message into the brain or translation of the message once it reaches the brain. Central Auditory Processing Disorder was initially the term used to describe the auditory processing disorders that occur in the central nervous system, i.e. the brain. Over time the term has been shortened to Auditory Processing Disorders, and these days CAPD and APD are essentially interchangeable.