Central Auditory Processing Disorder

What is Central Auditory Processing Disorder?

Auditory Processing Disorder otherwise known as Central Auditory Processing Disorder (CAPD) affects about 2-3% of children, who cannot accurately decipher what they are hearing. Children with CAPD have normal peripheral hearing, but there is a coordination breakdown within the auditory cortex of the brain. This means the when the auditory signal arrives in the brain, the neural processes involved in making sense of this information are distorted.

In a quieter environment (like at home), this disorder is not as obvious. However, when faced with the difficult task of extracting important auditory information from their teacher in a noisy, usually echoey classroom, a child with Auditory Processing Disorder will struggle. Noise and reverberation create distortion on top of distortion for this child, which is why they will exhibit behaviour resembling hearing loss.

Typical symptoms include:

Discovering CAPD

Sarah is an 8-year-old child who her teacher says doesn’t pay attention in class. She is frequently in trouble for misbehaving and not following instructions and seems to struggle more in noise and her overall academic performance is falling compared to the other children. Sarah’s parents are confused as she is otherwise a well-behaved child at home. Determined to get to the bottom of this, they ask her what is going on. ​Sarah says she cannot hear the teacher in class and gets confused when everyone is talking at once.

At this point, Sarah’s teacher recommends a hearing test, which is when her parents take her to an Audiologist who performs a thorough hearing assessment. The results indicate that her hearing is within normal limits in both ears. Furthermore, her speech perception scores in quiet with headphones are excellent for both ears at soft levels.

So, what’s going on? Why is Sarah finding it hard to hear in the classroom? Imagine being told that your child has normal hearing despite countless examples of listening difficulties. Imagine being that child. It can be a source of great frustration and emotional turmoil for everyone involved. Sarah’s scenario is very common for children who may have CAPD.

Testing for CAPD

Many different types of disorders fall within the ambit of CAPD; therefore testing can include a variety of tests. Not all tests have been found to directly relate to listening difficulty or academic performance and results can be affected by other problems. Fatigue is also a problem in some testing methods, as exhaustive test batteries can lead to unreliable results.

At Pristine Hearing, our test battery includes those that measure deficits proven to relate to listening difficulties and/or poor academic performance. Pristine Hearing takes a hierarchical approach to assessing CAPD; in a strategic method, only necessary tests are performed, considering previous results already obtained. Before any CAPD assessment occurs, Pristine Hearing will conduct a thorough hearing assessment (including micro-suction earwax removal) on your child to ensure there is no peripheral hearing loss. We perform CAPD assessment where there is no hearing loss identified and the child is at least 6 years old.

Our testing process involves:

  1. Spatial Processing Disorder Assessment

Spatial Processing Disorder is a type of CAPD which makes it difficult to use directional cues within sounds that we need to be able to separate background noise from the sound we want to hear. For instance, focusing on a teacher speaking in a classroom over noise of students. If your child is struggling to hear in the presence of background noise, then they may have Spatial Processing Disorder. Pristine Hearing offer the LISN-S test, developed by the National Acoustics Laboratory (NAL) to assess speech understanding in the presence of background noise. The good news is that children with SPD can undergo remediation by participating in a 10-week auditory training program developed by NAL in the form of a fun and interactive game called Sound Storm played on an iPad.

Research has shown that when children with SPD play this fun and interactive game twice a day (20 minutes per session), 5 days a week for 10 weeks, 90% of children will be able to improve their ability to hear in background noise such that they will be able to perform as well as they once did but with 10dB more noise. This amazing result and performance have been shown to extend beyond the end of the training period and be maintained long-term. For more information, please visit the NAL website.


  1. Short Term and Working Auditory Memory Testing

Short-term memory deficits have been linked to poor academic performance and increased reports of listening difficulties. Where SPD is not the cause of your child’s problem, poor working and short-term auditory memory could be creating listening difficulties in the classroom. After the LISN-S test, your Audiologist may proceed with an auditory short-term memory and auditory working memory assessment. This is measured using Number Memory Forward (NMF) which is a sub-test of the Test of Auditory Processing Skills – Third Edition (TAPS). This test was designed to assess how well a child can retain simple sequences of auditory information. Likewise, Auditory Working Memory has been linked with listening difficulties, academic problems and even listening fatigue.

To assess this, the TAP-developed, Number Memory Reverse (NMR) is used. If short-term memory deficit is identified, a remedial development program will be recommended. If not, additional tests will be required. Children with auditory memory deficits can improve their skills with a course of auditory training and memory skills development. Pristine Hearing recommends the software package Memory Booster, an interactive game played on the computer 3 times a week over 8 weeks. With different degrees of difficulty designed to push your child to develop different strategies that can improve their auditory memory skills, it has shown improvement in around 60% of children. For more information about Memory Booster, visit Dichotic Digits – Binaural Integration


  1. Amblyaudia or Dichotic Dysaudia Assessment

Lastly, if no SPD or memory deficits have been identified, your Audiologist will perform the Random Dichotic Digits Test (RDDT) and the Dichotic Word Test (DWT) to determine if your child has the auditory processing disorder known as Amblyaudia or Dichotic Dysaudia. Amblyaudia occurs when there is a significant asymmetry between how well each ear performs at binaural integration activities.

Dichotic Dysaudia occurs when both ears are weak at transferring auditory information to the correct brain hemisphere. A child with either of these deficits will struggle to hear in a noisy classroom and will generally have poorer attention than their peers. If a binaural integration deficit is found (either Dichotic Dysaudia or Amblyaudia), research has shown that using the auditory training methodology called Auditory Rehabilitation for Interaural Asymmetry (ARIA), a child or even an adult can be rehabilitated.

Pristine Hearing are the only accredited WA service provider of the binaural integration auditory training package CAPDOTS. Visit the CAPDOTS website for more information. To learn more about ARIA and Amblyaudia, here are some articles by leading researcher, Assistant Professor Deborah Moncrieff:

Diagnosis of Amblyaudia in Children

Evidence of Binaural Integration Benefits Following ARIA Training for Children

Care in Good Hands

Pristine Hearing takes a holistic approach when creating a treatment plan for your child. Auditory training options mentioned above help to improve a specific skill closely linked to real-life classroom performance, but we know some children are better served by integrating them with workable classroom strategies, including classroom modifications and communication tactics, remote microphones and/or sound-field systems to reduce the effects of noise, distance and reverberation.

To book a CAPD assessment, ​please call (08) 6336 7170 , book online or email us.