Q: There was a test developed by Australian Hearing’s National Acoustic Labs to assess the ability of children with suspected central auditory processing disorder (CAPD) to understand speech when there is background noise present. What is this, where is it available, how do you identify if a child has CAPD, and what is the treatment?

A: The name of the test is the Listening in Spatialized Noise - Sentences test, or LiSN-S. It is available in English speaking countries from Phonak. LiSN-S is used to diagnose a specific type of CAPD known as spatial processing disorder, or SPD. This is a reduced ability to selectively attend to sounds coming from one direction and suppress noise coming from other directions. You might expect a child to have SPD if they are having difficulty understanding speech in noisy situations, such as in the classroom.

The cause of SPD is so far unknown, but it is more likely to be present in children who have had prolonged or repeated middle ear infections (otitis media) during early childhood, despite full recovery of their hearing thresholds. Research at NAL with the LiSN-S has also shown that all people with a sensorineural hearing loss experience some degree of SPD. As with any form of CAPD, children with SPD can have an FM system fitted to improve the signal-to-noise ratio. NAL has also developed the LiSN & Learn auditory training software to remediate this condition in children with normal hearing thresholds. Research and clinical trials have found, for all children who completed the training, no evidence of SPD remaining by the end of the training.

The LiSN & Learn is available directly from the NAL website at http://shop.nal.gov.au/store/lisn-learn.html.