Auditory Processing Disorder

Do you ever sense that your child can hear you when it’s quiet, but they struggle to hear in noisy places? It’s possible that they have an auditory processing disorder (APD).

What is an auditory processing disorder?

An auditory processing disorder occurs when there is a defect in the auditory pathway between where sound is turned into nerve impulses (in the ear) and where sound is processed and perceived (in the auditory cortex of the brain).

As a result, all the sounds entering the ear at one time may not be sorted properly on their way to the brain, making it more difficult for the brain to register and respond to the important sounds within that mix — such as an instruction from a teacher.

How do we process sound?

We have a steady flow of different sounds entering our ears. For those without an auditory processing disorder, these sounds move along the auditory nerve into the brainstem, where they start to be filtered and sorted, and then into the auditory cortex. The auditory cortex exchanges information with other parts of the brain, and anything deemed useful (such as an instruction from a teacher or parent) is emphasised. Background noise is filtered out and discarded.

Those with an auditory processing disorder receive the same sounds but process them differently. Instead of picking out the important instruction, the filtering system allows other sounds to pass through. This makes it much harder for the brain to work out which sounds are the important ones.

It’s easy to see how this could be interpreted as a child not hearing in the first place, when actually they are “hearing” all the sounds, but are unable to process them in a meaningful way.

How can you tell if someone is having trouble processing sound?

Based on observing behaviour alone, it can be difficult to understand if a child is not hearing you, or if they are hearing you but not processing what you are saying. An auditory processing disorder may be misdiagnosed as a behavioural issue because it appears as if the child isn’t able to pay attention or isn’t hearing instructions. Auditory processing disorders can also cause problems socially — a child may have trouble communicating with friends in a noisy playground.

Signs of auditory processing disorder

KidsHealth identifies a number of behaviours to look out for as possible signs of an auditory processing disorder. Note that these same issues could also be caused by something else:

• Finding it hard to follow conversations or a series of instructions
• Being easily distracted or upset by loud or sudden noises
• Behaving better in quiet environments compared to noisy ones
• Having issues with reading, writing, spelling, or speech
• Appearing to be disorganised or forgetful

Can you test for auditory processing disorder?

Only an audiologist carrying out a range of diagnostic tests in a controlled environment can diagnose an auditory processing disorder. These tests can be tricky for children under age seven to understand, so formal diagnosis typically happens from around age seven onwards.

The results from an initial hearing screen can form the basis for further discussion about auditory processing disorders with an audiologist or speech pathologist, and can help parents and teachers respond to a child’s needs.

How can parents and teachers help children with an auditory processing disorder?

As with many conditions, early intervention is key. Some strategies that parents and teachers can implement include:

• Reducing background noise where possible
• Looking at the child when you speak to them (and asking them to look at you)
• Speaking simply and clearly, and a little more slowly
• Asking your child to repeat what you’ve said back to them, to ensure understanding
• Adding extra time to allow the child to process what you’ve just said
• Sitting the child at the front of the classroom
• Providing classroom aids, such as the teacher wearing a microphone or a classroom amplification system
• Consulting with a speech pathologist to help your child develop their speaking and language skills
• Exploring remediation programmes, such as computer-based auditory training

Sources: American Speech-Language-Hearing Association, KidsHealth, Purves et al. Neuroscience 2nd Edition.