Auditory processing disorder is usually first noticed in young children. It seems as though the child has a hearing problem but usually their hearing is normal.
What is auditory processing disorder?
Auditory processing disorder (APD) affects how your brain interprets sound rather than how sound is carried through the ear to the brain. The brain is unable to process sounds in the normal way. It can affect people of all ages, but often starts in childhood.
The severity of APD is very variable. Some children with APD have more difficulty than others. The effect of APD can be worsened by other conditions, such as dyslexia, attention deficit hyperactivity disorder (ADHD), and speech and language problems.
What causes auditory processing disorder?
The causes of APD aren't fully understood but research is ongoing to understand more about it. Some cases in children may follow hearing problems such as glue ear when they were younger. It may also be caused by a faulty gene, as some cases seem to run in families.
In both adults and children, APD is sometimes linked with brain damage from a head injury, stroke, brain tumour or meningitis. It may also follow problems during and shortly after birth, such as a traumatic birth, severe jaundice or a brain haemorrhage.
Some cases in adults have also been linked to changes in the brain's ability to process sounds as we get older. It may also be associated with long-term progressive conditions that affect the nervous system, such as multiple sclerosis.
The rest of this leaflet focuses on developmental APD in children.
How common is auditory processing disorder?
It is not known exactly how common APD is. It is estimated that between 3 and 5 out of every 100 children are affected to some extent by APD. However, the difficulties caused by APD vary from being mild to being severe.
What are the symptoms of auditory processing disorder?
Parents may suspect that their child is not hearing or listening properly at quite a young age, but it is often at school that the difficulties become more obvious.
APD can affect people in many different ways. A child with APD may appear to have a hearing impairment, but this isn't usually the case and testing often shows their hearing is normal.
Children with APD are most likely to have difficulty in understanding speech in noisy places, like a classroom. They may also have trouble concentrating and reading when there is a lot of background noise. APD also often makes it hard to distinguish similar sounds from one another, such as 'cool' and 'call'.
These problems may lead to difficulty in understanding and remembering instructions, speaking clearly and developing reading skills.
What are the tests for auditory processing disorder?
The usual hearing tests aren't effective at diagnosing APD because they're usually carried out in a quiet room without distractions and don't test the ability to hear in normal day-to-day situations. Although children with APD may seem to have a hearing impairment, this is not usually the case, as hearing for pure tones is within the normal range when tested.
Therefore more complex tests are needed, including the ability to hear with different levels of background noise, understand poor-quality speech and detect subtle changes in sound.
Other tests that may be used to help diagnose APD include:
- Electrode tests. Headphones are used to listen to sounds and electrodes are placed on your head to measure your brain's response.
- Speech and language assessments.
- Assessments that test the way your brain processes information (cognitive tests).
What are the treatments for auditory processing disorder?
There are a number of ways to reduce the effects of APD on everyday life. These include:
Help from others
It is helpful for other people to:
- Get your attention and face you before they talk.
- Speak clearly and at a normal speed (not too fast or too slow).
- Emphasise speech to highlight the key points of the message.
- Repeat or rephrase the sentence if needed.
Other strategies that might be particularly useful when talking to children with APD include:
- Not using long sentences.
- Using pictures to help them understand what you mean.
Training programmes to address specific issues or to improve listening and concentration can be very effective.
Auditory training involves using special activities to help improve the way the brain analyses sounds. This can be done with the help of a trained professional, or by using a computer program.
Auditory training includes identifying sounds and guessing where they're coming from, or trying to focus on specific sounds when there's some slight background noise. The tasks can be adapted for people of different ages. Children can learn through games or by reading with their parents.
Adjustments at school and at home
Adjustments that can be made at school to make things easier include:
- Sitting near the front of the classroom.
- Reducing background noise.
- Asking the teacher to check that your child understands what they're being told.
- Using written instructions in addition to verbal instructions.
- Wearing a radio receiver or having a speaker on the desk at school that is linked to a small microphone worn by their teacher may help.
Adjustments at home that will help include:
- Reducing background noise, such as from the television or radio.
- Asking your child to repeat back what you have said is also helpful.
- Rooms with hard surfaces cause echoes, so rooms with carpets and soft furnishings work best.
What is the outcome (prognosis)?
Many people with APD find it gradually becomes less of an issue over time. This is because they develop the skills to deal with it. Although children may need extra help and support at school, they can be just as successful as their classmates.
Further reading and references
Iliadou VV, Ptok M, Grech H, et al; A European Perspective on Auditory Processing Disorder-Current Knowledge and Future Research Focus. Front Neurol. 2017 Nov 218:622. doi: 10.3389/fneur.2017.00622. eCollection 2017.