AUDITORY PROCESSING DISORDER
What is Auditory Processing?
To understand what an Auditory Processing Disorder (APD) is, we first have to understand what auditory processing is. Auditory processing refers to the operations our brain carries out after it has been heard by our ears. This process turns the sound waves we hear into words and ideas. The auditory pathway starts at our ears and travels up the auditory nerve, through a number of specialised areas all the way to the auditory cortex (the area in the brain that does the hearing).
Auditory processing allows us to do a number of things, such as helping with awareness and localisation of sound, where we are able to detect the presence of sound in the environment. The direction and the distance of the sound source allows us to know where someone is speaking from. It helps with integrating information across time allowing us to hear the pitch and loudness, meaning we can comprehend melody in speech, which allows us to understand what is said better. Also our ability to detect changes and small gaps in speech (resolution) allows us to pick up the subtle differences in speech, which is important for reading and spelling. For example being able to pick up the difference of the voiced “p” in pat vs. the unvoiced “b” in bat. Auditory processing allows us to use discrimination and ordering so we are able to pick up the sequencing of sounds so we can notice the difference between similar words like “lost” and “lots” just by the ordering of the sounds “t” and “s”. It gives us the ability to listen in background noise, where we can focus on the target speaker and ignore other speakers around us. This is an especially important skill when in a classroom. It is important to note there are other things that influence our ability to hear, such as attention, memory our language abilities.
What is Auditory Processing Disorder (APD)?
The formal definition is: an ability to hear information but a difficulty attending to, storing, locating, retrieving and clarifying that information to make it useful for academic and social purposes. This can have a significant effect on academic performance and language acquisition.
Therefore APD is a breakdown somewhere in the auditory pathway which affects how we are able to hear sounds-more specifically speech. Often this is why APD is referred to as a hearing problem where the “brain can’t hear”.
Prevalance of APD:
In New Zealand the prevalence is around 5% in the general population (1 in 20) and it tends to affect boys more than girls.
Causes of APD:
The cause of APD is largely unknown and it appears that there is no single cause common to all children. A lot of research has suggested that APD is related to a maturational delay (delay in the development) of the auditory processes of the brain, used to deal with complex auditory information.
If we do not get sensory stimulation during critical development periods then this deprivation of hearing in infancy can mean the development of hearing does not happen normally. There is some research which indicates prolonged otitis media (sometimes referred to as "glue ear") can result in APD, presumably because hearing has been disrupted during important developmental periods.
There may also be heredity (family history) related cases and birth related factors which may played a role in APD.
What does APD sound like?
This clip is from the viewpoint of a child with APD, trying to following instructions in the classroom. See if you can do the task! Click here to view.
Untreated effects of APD:
Children often fall behind academically and socially as they only hear part of what has been said or they don’t understand the intent of the speaker which makes it hard for them to make friends. Some areas where you may notice difficulties are:
- Reading, writing and spelling difficulties
- Problems with note taking
- Not performing to potential
- Problems with phonics and speech sounds
- Misunderstanding in class
- Withdrawn socially
- Some behavior problems
- Fear of failure
- Diminished self esteem.
Signs your child may have APD:
- Difficulty comprehending spoken language unless clear and simple
- Difficulty hearing when there is any background noise
- Poor listening skills (often presenting as a child with hearing loss)
- Slowness in processing spoken language
- Poor auditory memory (unable to follow instructions)
- Insensitivity to tone of voice
- Sensitive to loud sounds or noisy situations
- Extreme tiredness after school
- Problems with comprehension, language, phonics, spelling, reading or writing
- Inappropriate responses to questions
- Use of a loud voice
- Easily distracted
For a more comprehensive checklist click here.
How we diagnose APD:
- APD can only be diagnosed by an audiologist
- Not all audiologists specialise in APD, so you will want to find someone who does and who has experience with APD (Wanita has been assessing and helping children with APD for a number of years)
- A full diagnostic assessment needs to be carried out-this is usually about a 2 hour assessment
- The child is given a number of listening tasks which look at all aspects of the auditory pathway
- Results are usually given at the time of appointment and recommendations for each particular child are given
- Assessments are usually only done when a child is 7 years old, given the complexity of the tasks
Strategies to help:
There are a number of ways to help children with APD. This document has extensive ways to help. Some children may benefit from a personal FM system and if so, we can discuss this with you. There is also a great support group, where you can get in touch with other parents. They are called the Hear for Familes-APD group and to view their page click here. Further advice on recommendations and funding options will be discussed at your child's appointment.
APD can in most cases be treated or managed due to the fact that we can re-train the brain to listen. The brain can be stimulated to put down more neural pathways (called neuroplasticity). Due to this ability we are able to help improve a child's listening skills and the hearing difficulties they are having and then with other specialists we are able to then help the child catch up with their peers in terms of the language and learning they have missed out on.