Triple L Paediatric Speech Pathology and Audiology, Redlands City

What Is Auditory Processing Disorder?

Auditory Processing Disorder (APD) encompasses a range of symptoms that can have a significant functional impact on a person's listening, language and literacy.

Auditory Processing Disorder (APD) is a ‘heterogenous’ hearing disorder, meaning it is very diverse in character and may encompass a range of possible presenting symptoms having significant functional impacts on a child or adult’s listening, language and literacy skills.

Auditory Processing Disorder Explained

APD results from atypical processing of information (ability to attach meaning to incoming sounds) at any point along the auditory neural pathway (the pathway that carries signals from the inner ear to the brain along the auditory nerve), and within the primary auditory cortex of the brain.

Simply put, our peripheral hearing system (the outer, middle and inner ear) enables us to hear sounds i.e. it is the doorway to hearing sounds, while our auditory processing system is the pathway to the brain and within the brain that helps us to listen i.e. fully attach meaning to the sounds that we hear as well as recall these sounds at a later stage.

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APD as a Diagnosable Disorder

In 2016, the term APD became fully recognised in the US, Canada, and South Africa with an International Classification of Disease Code (ICD) meaning it is now internationally recognised as a diagnosable disorder. However, despite many studies attempting to isolate whether auditory processing takes place centrally in the brain or whether it takes place at particular points along the auditory neural pathway, no clear boundaries have yet been able to be established between whether it is a central or peripheral process i.e. there is no clear line between where auditory processing ends and where language and higher cognitive function begins.

While APD has often been referred to as Central Auditory Processing Disorder, it is now more commonly being referred to world-wide as ‘Auditory Processing Disorder’ indicating that its symptoms may be due to both peripheral and/or central impaired functioning.

For these reasons, both Canada and New Zealand have adopted the International Classification of Functioning, Disability and Health (ICF) approach to describing APD whereby the focus is on the functional impacts on a person in the context of their specific environment rather than the exact cause of the disorder or difficulty. 

Assessment and Management of APD

Assessment and management of APD should therefore also focus on the functional impact for the individual, and early identification and management of APD are critical in minimising these functional impacts.

Because of the varying symptoms and functional impacts of APD, it is important for a multi-disciplinary approach to be adopted when assessing and remediating this disorder.  This begins with the Audiologist and the Speech Pathologist, with the Speech Pathologist being able to identify many of the functional impacts of an Auditory Processing Disorder and how these may be managed. Teachers of the Hearing Impaired can also support children with APD within the educational setting, especially when management options include some form of amplification e.g. a remote microphone system.  In order for a management plan to be effective it may also include input from an Occupational Therapist and a Psychologist.

Many of the possible presenting symptoms of APD can be identified by parents or teachers.  See our checklist for a description of these symptoms. 

Some of these symptoms can overlap with the symptoms of attention disorders or difficulties such as ADHD. Please see our quiz to determine whether your child is more likely to be experiencing difficulties in attention or auditory processing.

APD may occur alongside many other learning and developmental disorders including:

  • Unilateral hearing loss (these children will often be described as having ‘functionally normal hearing’ however a unilateral hearing loss can impact on a child’s ability to hear in difficult listening environments such as a noisy classroom)
  • Dyslexia and Dysgraphia
  • Language disorders
  • Visual processing disorders (difficulties tracking sequentially from left to right e.g. when reading and writing, visual discrimination difficulties e.g. discriminating between the b, d and p graphemes and visual memory difficulties e.g. recalling visual grapheme/letter patterns for particular sounds or recalling visual patterns of irregular spelt sight words as a whole)
  • Attention Deficit Hyperactivity Disorder (ADHD)
  • Autism Spectrum Disorder (ASD)

As a result of APD co-existing with the above disorders, it is therefore highly recommended that a child with a diagnosis of one or more of the above disorders be referred for an auditory processing screen to ensure that they are receiving the best possible support in terms of their listening.

Flowchart To Represent How Auditory Processing Disorder/Difficulties Impact On Function

Impact of APD on Function