What is Central Auditory Processing Disorder (CAPD)?

Auditory processing disorder (APD), also known as central auditory processing disorder (CAPD), is a term used to describe a variety of disorders that affect the way the brain processes auditory information (Musiek et al, 2010).

 

Common behaviours and symptoms include:

  • difficulty understanding speech in the presence of competing background noise
  • problems with the ability to localize the source of a sound
  • difficulty hearing on the phone
  • inconsistent or inappropriate responses to requests for information
  • difficulty following rapid speech
  • frequent requests for repetition and/or rephrasing of information
  • difficulty following directions
  • difficulty or inability to detect the subtle changes in prosody that underlie humour and sarcasm
  • difficulty learning a foreign language or novel speech materials
  • difficulty maintaining attention
  • a tendency to be easily distracted
  • poor singing, musical ability, and/or appreciation of music
  • academic difficulties, including reading, spelling and/or learning problems
  • (Musiek et al, 2010).

Literature from the USA, Australia, South Africa, and UK would indicate that 3-10% of the population have some degree of this condition (Medical Research Council Institute of Hearing Research, UK, 2004). Currently there are no statistics on the number of people in Ireland presenting with CAPD

 

Assessment & Treatment of CAPD

Audiologists, speech and language therapists, psychologists, teachers, parents and other health professionals all have a role in identifying CAPD (Palfery & Duff, 2007).

Bellis (2007) describes 3 stages within the assessment process:

1. Screening assessment
2. Diagnostic assessment
3. Differential diagnosis
1. Screening Assessment
This phase involves use of reliable and valid standardized screening tools which can be administered by health and/or education professionals. Parents will also be involved in this phase. Screening assessments should not be used for diagnostic purposes. The purpose of screening is:
• To determine the need for further testing
• To reduce over-referrals and inappropriate referrals

2. Diagnostic assessment
This phase requires the use of specialized diagnostic tests and equipment which can only be administered by an audiologist. Speech and Language Therapists and other professionals collaborate in this assessment process.

3. Differential Diagnosis
The purpose of differential diagnosis is to review and integrate all of the assessment results from the various professionals to arrive at a diagnosis. A diagnosis of CAPD is only made when specific, clear and distinct auditory deficits are identified by the key professionals involved in the assessment process.

 

Treatment of CAPD

Current best practice advocates that treatment for children with CAPD has three key components and is referred to as the CAPD Management Tripod (Ferre, 2006) which includes environmental modification, compensatory strategies and direct intervention.
1. Environmental Modification
This involves modifying the environment to enhance the sound signal (Ferre, 2006).
This can be achieved by:
• Reducing classroom noise
• Using assistive listening devices to enhance the speech signal reaching the child’s ear, for example, Soundfield FM systems
• Reducing the rate of presentation of verbal material and repetition of material
• Paying attention to the seating arrangements within the classroom by positioning children with CAPD nearer to the sound source
2. Compensatory Strategies
Children may need to learn strategies to help them compensate for their auditory deficiencies. The following strategies may be useful:
• Visual cues can help children with CAPD
• Pre-teaching or previewing material will enhance familiarity with the material
• Use of books on tape
• Scheduling breaks in the listening day to help minimize auditory overload
• Providing additional time for class examinations.
3. Direct intervention
Children with CAPD may benefit from on-going direct intervention from professionals such as Speech and Language Therapists, Resource Teachers and other professionals.
Conclusion

In both the area of diagnosis of CAPD and in the area of treatment approaches for CAPD, there is strong evidence of effectiveness (Chermak, 2007).

 

References:

Bellis, T. (2007). Assessment and management of central auditory processing disorders in the educational setting – from science to practice. (2nd Edition) Delmar, NewYork: Thompson Learning.

Chermak,G.(2007) Our Understanding of APD .Opening Plenary Session at American Speech-Language-Hearing Association Virtual Conference on the Web.

Ferre,J.M. (2006) Management Strategies for CAPD. In T Parthasarathy (Ed.), An Introduction to Auditory Processing Disorders in Children. NJ: Lawrence :Earlbaum Associates.

Medical Research Council Institute of Hearing Research Nottingham UK (2004) Auditory processing disorder. Retrieved from the web on 31 January 2013, from
http://www.infosheets.CAPDuk.org/mrc_CAPD.htm.

Musiek, F.E., Baron, J.A, Bellis, T.J., Chermak, G.D., Hall, J.W., Keith, R.W., Medwetsky, L., West, K.L., Young, M. and Nagle, S (2010) “Clinical practice guidelines – diagnosis, treatment, and management of children and adults with central auditory processing” American Academy of Audiology

Palfery, T.D.& Duff,D. (2007). Central auditory disorders, review and case study. L’Axone (Axon), 28(3), 20-23.

 

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