Auditory processing disorder (APD) affects how the brain interprets sound (rather than how sound is carried through the ear to the brain). It’s usually diagnosed in childhood, but sometimes it’s only picked up later as a teenager or even an adult.
There’s no medicine or procedure that can ‘cure’ APD, but if you have this condition, there are things you can try to reduce its effects on your everyday life. If your doctor thinks it’s appropriate, you may be referred to Great Ormond Street Hospital (GOSH) for specialist treatment, as GOSH runs one of the few paediatric APD clinics in the UK.
What is APD?
Your ear is made up of three parts: the outer ear, the middle ear and the inner ear.
You hear because sound waves enter your ear canal and cause your eardrum to vibrate. The sound then passes through your middle ear via the three small bones of hearing (ossicles) on to your inner ear, which is filled with fluid. The movement of the fluid in your cochlea stimulates the hair cells inside it to trigger a nerve impulse, which is carried to your brain by the auditory nerve. Your brain then interprets these nerve impulses as sound.
When someone has APD, sound enters the ear canal and passes through the middle and inner ear as usual. It then travels to the brain through the auditory nerve. Once the sound has arrived in the brain, there could be problems with interpreting it eg localising where the sound is coming from or listening to someone speaking when there is noise in the background.
APD is a ‘spectrum’ because each person is affected in a different way and to a different degree. Some young people with APD have a greater range of difficulties than others and the effect of APD on an individual can be made greater by the presence of other conditions like dyslexia, language processing difficulties, poor attention and poor short-term memory.
Doctors don’t really know what causes APD but research is going on to understand more about it.
It might have something to do with your genetics, as parents sometimes report having had similar problems when they were young. It might also be caused by the brain being ‘wired’ slightly differently in some children who had lots of ear infections when they were little, so that message signals are passed from cell to cell less effectively than usual.
Other conditions can affect children alongside APD including dyslexia, attention deficit with or without hyperactivity disorder and speech/language problems.
We’re not sure how common APD is, but estimates from around the world suggest three to five per cent of children have APD to some degree.
As a young child, your parents may have suspected that you weren’t hearing or listening properly, but it’s often when children start school that the difficulties become more obvious. Although people with APD may seem to have a hearing impairment, this isn’t usually the case as tests usually show that hearing for pure tones is within the normal range.
If you have APD, you are most likely to find it difficult to understand speech, especially in noisy environments like in a noisy classroom or crowded shopping centre. You may also have trouble concentrating and reading when background noise is present. These problems may make it difficult for you to understand and remember instructions, speak clearly, and develop reading skills. If you’re at school, your teachers may have noticed these problems. However, even if you have all these problems, it is not necessary that you will have APD, because these difficulties may also be due to other problems that affect communication.
A common hearing test may not detect APD. This is because the test is carried out in a quiet room with minimal distractions. Other more complex tests are needed to diagnose APD, such as hearing speech in different levels of background noise, pitch discriminations and sound pattern recognition tests, tests to determine the ability to detect subtle changes in sounds etc, with comparison of your results with other people of your age. You may also need to have additional tests to assess your language abilities, your memory and/or your attention.
There is normally no medicine or procedure that can ‘cure’ APD except in a few specific conditions, although some could improve with time. But there are some strategies that could help to reduce the effects of APD on your everyday life. Training programmes address specific issues, or to improve your listening and concentration, can be very effective if practised regularly.
If you’re at school, you can make things easier by asking the teacher if you can sit near the front of the classroom. Also, if you struggle to hear verbal instructions, ask your teacher to provide written instructions.
Making adjustments at home can also be helpful, such as keeping background noise from the television or radio to a reasonable level.
With the right coping strategies in place, there's a good chance that you will cope better with your APD, but sometimes APD can improve as you get older. With reasonable adjustments, most young people with APD have a successful school and work life.
GOSH runs a specialist APD service so a referral would need to follow the GOSH Audiological Medicine department's referral criteria. It’s also important to get a routine hearing test to show that your hearing is normal before asking for a referral.
If you have cognitive and language difficulties appropriate assessments by an educational psychologist and a speech and language therapist need to be carried out before the referral.
This is an NHS clinic but private referrals are also accepted.