KidsAudiologist

Normal hearing but not hearing normally?

Posted on: August 23, 2011

Updated 22nd July 2016 to include new links to useful websites and interesting articles.

Parents worried about their child’s hearing often bring them into the audiology clinic only to be told that their hearing test result is well within the normal range of hearing. That there is nothing to worry about can be a great relief to some parents – in many cases the child has been suffering with a bout of ‘Glue Ear’ that has now resolved. For others this can be a very frustrating experience because they know their child doesn’t behave like their normally hearing friends. They may have difficulties with listening, or making sense of sounds that are heard, and this may be particularly bad in environments with a lot of background noise. Some parents realise their child has difficulties with understanding from an early age, but often APD becomes more obvious when children start school. At this point it is helpful to remind ourselves that ‘hearing’ and ‘listening’ aren’t the same thing. The ability to listen involves memory, learning, vision and attention, as well as hearing. If any of these functions are impaired then listening may be affected. One possible diagnosis is Auditory Processing Disorder (APD). Although first described in the 1970’s APD is still a relatively new player in the audiological field. Unfortunately this means that it is not widely understood, there are no universally used test procedures, and many audiology services do not test for the condition or offer any re/habilitation support. Over the years other similar names have been (and still are) used including central auditory processing disorder (CAPD) and obscure auditory dysfunction (OAD) which can make it difficult for families to find information easily. A letter to the editor in the July 2011 edition of the International Journal of Audiology “What’s in a name? APD by any other name would not smell so sweet” outlined some of the problems.

The British Society of Audiology’s APD Special Interest Group published a position statement and practice guidance documents (2011) to help inform audiologists and other interested parties of the latest evidence on APD, provide a consensus interpretation of the evidence, intended to inform current clinical understanding and practice. It’s a bit technical but here goes:

  • “APD is characterised by poor perception of both speech and non-speech sounds. Auditory ‘perception’ is the awareness of acoustic stimuli, forming the basis for subsequent action. Perception results from both sensory activation (via the ear) and neural processing that integrates this ‘bottom-up’ information with activity in other brain systems (e.g. vision, attention, memory). Insofar as difficulties in perceiving and understanding speech sounds could arise from other causes (e.g. language impairment, non-native experience of a particular language), poor perception of speech alone is not sufficient evidence of APD.
  • APD has its origins in impaired neural function. The mechanisms underlying APD can include both afferent and efferent pathways in the auditory system, as well as higher level processing that provides ‘top-down’ modulation of such pathways.
  • APD impacts on everyday life primarily through a reduced ability to listen, and so respond appropriately to sounds. The term ‘listening’ has been used to imply an active process while ‘hearing’ implies a more passive process; it is possible to hear without listening attentively.
  • APD should be assessed through standardized tests of auditory perception. There are currently no generally agreed ‘gold standard’ methods to assess APD, but these are essential to move the field forward. Note that ‘testing’ may include both direct and indirect measures such as questionnaires.
  • APD does not result from failure to understand simple instructions. Primary impairments for which auditory difficulties may be a ‘secondary’ or ‘trivial’ consequence include medical problems not affecting the ‘mechanisms underlying APD’ and generalised medical/psychological problems that render a label of APD impossible, inappropriate or irrelevant (e.g. severe mental impairment).
  • APD is a collection of symptoms that usually co-occurs with other neurodevelopmental disorders. Like other such symptoms (poor language, literacy or attention, autism) APD is often found alongside other diagnoses.”

So what should you do if you think your child has APD?

First of all ask your GP to refer you to a doctor who specialises in childen’s hearing problems. This will probably be a consultant in audiovestibular medicine, a paediatrician specialising in audiology, or a paediatric audiologist.

Children with APD usually have normal intelligence. The cause of APD is often unknown but it is often associated with conditions such as dyslexia, attention deficit disorder, autism spectrum disorder, specific language impairment, pervasive developmental disorder, or developmental delay.

Where can you get further information and support?

The British Society of Audiology publish a leaflet ‘Auditory Processing Disorder in Children’ (2015)

APDUK is a support group run by adults with APD and parents of children with APD. Their aim is to promote an increased understanding of APD in the UK by both the professional establishment, especially in the fields of education and employment, and the general public. They provide written information, a helpline and a web-based discussion forum. If your child is already at school and you’re having trouble accessing additional support then contact the Independent Panel for Special Education Advice (IPSEA) who provide free and independent legal advice and support in England and Wales regarding educational needs.

Useful websites & interesting articles

British Society of Audiology (BSA) / Auditory Processing Disorder (APD) Special Interest Group for interested professionals

Evolving concepts of developmental auditory processing disorder (APD): A British Society of Audiology APD Special Interest Group ‘white paper’   International Journal of Audiology Vol 52, Issue 1, 2013

British Society of Audiology’s Audacity magazine (Issue 2 December 2013) includes two useful articles on understanding APD and progress towards a gold standard clinical assessment:

  • pp32-35 Auditory Processing Disorder; the pursuit of a gold standard test, Dr Johanna Barry
  • pp36-38 Auditory Processing Disorder; are you keeping up? Dr Wayne J Wilson

Briefing Paper: Auditory Processing Disorder – An Education Response, NatSIP, BSA, & BATOD, May 2015

The Institute of Hearing Research‘s current research studies into APD

American Speech-Language-Hearing Association “Understanding Auditory Processing Disorders in Children”

Auditory processing disorders and auditory/language interventions: an evidence-based systematic review Language, Speech, and Hearing Services in Schools Vol.42 246-264 July 2011.

“The Difference Between Auditory Processing Disorder and Specific Language Impairment”  summary of Ferguson MA, Hall RL, Riley A, Moore DR (2011) Communication, Listening, Cognitive and Speech Perception Skills in Children With Auditory Processing Disorder (APD) or Specific Language Impairment (SLI). Journal of Speech, Language and Hearing research 54 (2):211-227.

Issues in diagnosis and management of auditory processing disorders – including spatial processing disorder lecture by Dr Harvey Dillon recorded at the Paediatric Masterclass 30th April 2016 in Greenwich (organiser Jay Jindal, Director of Audiology Planet)

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1 Response to "Normal hearing but not hearing normally?"

This is really useful, thanks for your concise summary of this complex disorder. I am sure I will be back to visit your links and references!

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