Audiology Committee ( Guidelines )
Answers by Associate Professor Danielle Tomlin to questions that a professional may want to know about Auditory Processing Disorder (APD)
What are the latest test battery approaches?
- It is important as a health professional to keep asking this question! It’s a constantly evolving field, and new tests are being developed and evidenced all the time. Currently a test battery with a range of behavioural tasks that target the domains of AP is recommended. In order to interpret these results and the listening deficits described screening cognitive assessments are also recommended. Some centres include evoked potential assessments. These are predominantly to rule out a neurodegenerative condition impacting the auditory nerve and causing the observed listening difficulties. There are however no evidenced evoked potential assessments for an accurate diagnosis of an auditory processing deficit.
What are the latest management approaches?
- Again this is another important aspect to keep re-visiting, as it is constantly evolving. Currently there are several deficit specific auditory training programs available that have high level evidence supporting their use, in the case where that deficit has been identified. Another approach receiving a lot of interest, with a growing body of evidence is the use of remote microphone technology to target the identified listening difficulties and improve a child’s access to target speech (particularly in the classroom).
Are there any biomarkers available?
- Currently no. There are several being investigated as proving an objective measure of listening difficulties, such as speech in noise deficits, or cortical immaturity, but to date none have been clinically evidenced to identify auditory processing deficits.
How common is APD?
- Given the range of test batteries an approaches to diagnosis, no one prevalence figure is agreed on. Most commonly reported in 5-7%, but this will vary with age, and be more common in younger school age brackets, and then again increasing incidence above 70 years of age.
Are there normative values available?
- This question should always be asked of any test under consideration of inclusion, and wherever possible population specific norms should be utilised.
Should we include cognitive assessments in our testing?
- Yes, if possible. It is important to be able to determine the role cognitive skill deficits such as attention or memory maybe contributing to the observed test results and the reported listening difficulties.
Is a particular management approach proven to be effective?
- This question should always be asked of any intervention under consideration. What research has been undertaken, and was it an independent body? What is the level of this research; was it a randomised control trial, what was the sample size? Has it been peer reviewed? What were the conclusions?
What are classroom strategies to employ?
- This will depend on the design of the classroom, but strategies such as preferential seating, sound field or remote microphone systems and acoustic treatments will all serve to improve the signal to noise ratio. Strategies such as providing supportive visual information, promoting self-advocacy and allowing longer time to complete tasks could also be considered.
What are the classroom behaviours that would suggest an APD assessment is appropriate?
- It is important to recognise that the presentation of an auditory processing deficit can look very similar to other behavioural and developmental disorders. The behaviours typically associated with APD, and likely to trigger a referral for assessment (not a diagnosis) include difficulty listening in noise, concentration difficulties, literacy delays, difficulty following instructions and poor listening skills.
- Wilson, W. J. (2018). Evolving the concept of APD. International journal of audiology, 57(4), 240-248.
- Keith, W. J., Purdy, S. C., Baily, M., & Kay, F. M. (2019). New Zealand Guidelines on Auditory Processing Disorder. New Zealand Audiological Society.
- Moore, D. R. (2018). Auditory processing disorder (APD). Ear and hearing, 39(4), 617.
- Sharma, M., Purdy, S. C., & Humburg, P. (2019). Cluster analyses reveals subgroups of children with suspected auditory processing disorders. Frontiers in Psychology, 10, 2481.
- Sharma, M., Purdy, S. C., & Kelly, A. S. (2009). Comorbidity of auditory processing, language, and reading disorders. Journal of Speech, Language, and Hearing Research.
- Sharma, M., Purdy, S. C., & Kelly, A. S. (2012). A randomized control trial of interventions in school-aged children with auditory processing disorders. International journal of audiology, 51(7), 506-518.
- Tomlin, D., Dillon, H., Sharma, M., & Rance, G. (2015). The impact of auditory processing and cognitive abilities in children. Ear and Hearing, 36(5), 527-542.