What is (Central) Auditory Processing Disorder?
Auditory Processing Disorder (APD) is a complex problem with the ability of the brain to interpret sounds, most notably speech. An affected person may perform well on a normal hearing test (beep test) because the test does not require the use of many auditory processing abilities. However, a task that requires many auditory processing abilities, such as hearing speech in background noise, can be much harder or impossible.
How Common is APD?
It is estimated that 2-3% of children have a form of APD. Boys are more likely to have APD (Chermak and Musiek, 1997).
What are the Symptoms of APD?
There are many potential symptoms of APD. Not every person will present with all symptoms. There are also many symptoms that may relate to a different condition, e.g. a behavioural condition. As a guide, a child should have 2 or more symptoms to be considered for APD testing.
- Difficulty hearing in the presence of background noise
- Difficulty following long conversations or multi-step instructions
- Difficulty hearing people they are unable to see, e.g. on the phone
- Difficulty remembering verbal information
- Difficulty learning a foreign language
- Distractibility in noisy places
- Being disorganised
- Trouble with reading, writing or spelling
- Inability to focus attention or give divided attention
- Lack of music appreciation
How is APD Assessed?
At Canberra Audiology APD is assessed after a normal hearing test has been performed. This is to rule out a problem with hearing. Following this, a detailed history is taken and a series of tests are performed where the person is required to listen to different sounds, words or sentences and report back on what they hear. Testing takes 2 – 2.5 hours. For children we recommend testing is split into at least 3 parts. For adults we recommend testing is split into 2 parts. This is because the tests are most accurately performed when attention levels are high.
Who Can be Assessed for APD?
For adults, anyone up to the age of 65 years old can be tested. The upper limit of testing is 65 years because after this age many APD tests will be inaccurate due to natural changes in the way that the brain functions beyond this age.
For children, comprehensive testing can be performed once they are 7 years old. This is because the tests can be quite challenging for young children, plus the normal-range for very young children is too large for us to determine whether an APD may be present or not. Screening testing can be performed on children of 6 years of age if there is a strong indication of possible APD from their history.
It is recommended that all children being assessed by an audiologist for an APD also have assessments with an Educational Psychologist and a Speech and Language Pathologist. This is because the symptoms of an APD can be very similar to other disorders, e.g. ADHD or a speech/language disorder. As part of a comprehensive assessment, these other potential disorders should be tested for.
Treatment for APD
If a patient is diagnosed with an APD there are many different treatment options available. The type of treatment offered depends on the type of APD that may be present. However, with all types of APD a “management tripod” approach is recommended. This includes:
- Environmental modification – to improve the perception of a person’s voice
- Compensatory Strategies – can assist listeners with APD to compensate for their condition
- Direct Intervention – focusses on correcting or improving the process in the brain responsible for the APD
For more information on APD assessment and treatment options please contact us on (02) 6156 4474.