The ability to understand spoken language involves not only the ability of the ear to detect sounds, but also the ability of the brain to recognize, interpret, and use the acoustic information in our environment. Auditory Processing Disorder (APD) formerly referred to as central auditory processing disorder (CAPD) is an abnormality in the brain’s ability to turn sound into usable information. Individuals with Auditory Processing Disorder have a neurological defect in the pathways from the auditory (hearing) nerve through the higher auditory pathways in the brain. This causes distortion and/or delay in auditory signal transmission. The inaccurate coding of sound leads to poor ability to filter and process sounds and words. Since these individuals struggle to process (or interpret) what they hear, it causes listening problems that often mimic a hearing loss.
Most people with Auditory Processing Disorder will usually pass a hearing test and often have normal intelligence. However, since the brain receives sounds incorrectly, they may not recognize subtle differences between sounds in words (duh and guh for example), and they may have difficulty using those sounds for speech and language.
Children with Auditory Processing Disorder have trouble screening out background noise, so surrounding sounds from air conditioners, hallways, and noisy environments such as gymnasiums make it very difficult to understand speech. It’s like listening to a radio station with static or other stations interfering with the reception. In addition, these children typically try so hard to understand that they often forget parts of what they hear.
There are many different types, areas, or categories of auditory processing deficits that can lead to what we call Auditory Processing Disorder, and no two individuals are exactly alike in their symptoms. Auditory processing evaluations are most often performed on school-age children, although children can be tested for early signs of weaknesses as young as age 3 and many adults are also tested.
Some of the more common problems in individuals with APD include:
- Difficulty understanding speech with competing talkers or background noise
- Difficulty following multiple-step or lengthy oral directions
- Mishearing auditory information
- Frequent requests for repetition and/or rephrasing of information
- Trouble hearing subtle differences between sounds in words
- Difficulty maintaining attention when listening to verbal information
- Problems comprehending and/or remembering spoken information
Since there are different types of APD, symptoms will vary from person to person. See our full list of symptoms including the educational impact of auditory processing disorder and symptoms by age group.