I have a 4 year old son with a dx of Apraxia. I have asked for testing for CAPD, but am told that he is too young for the testing. I asked our developmental...
Dan S. replied:
Jessica Szahowski, two points: 1) No diagnosis of (C)APD is valid until Auditory Neuropathy Spectrum Disorder (ANSD; formerly called Auditory Neuropathy/Dys-synchrony (AN/AD)) has been *conclusively* ruled out; 2) Since you're in Williamsburg, you can drive 45 minutes west on I-64 to MCV for ANSD testing, as they have a good audiology shop.
Dan S. replied:
Jessica: The testing for ANSD is completely passive, and in fact is part of universal newborn hearing screening (at least the ones that meet standards). The screening test is to measure acoustic (stapedial) reflex thresholds, compensating for ear canal volume for ipsilateral (same side) measurements; while the confirming test is a special click ABR using alternating compression & rarefaction clicks. Here is a quick copy/paste of information I keep in a text document: Auditory Neuropathy Spectrum Disorder (ANSD; previously called Auditory Neuropathy/Auditory Dys-synchrony (AN/AD)) is indeed a relatively new diagnosis: It is a complicated hearing disorder in which sound enters the inner ear normally, but the transmission of signals from the inner ear to the brain is impaired, where the cochlea becomes unsynchronized from the brain. It can affect people of all ages, from infancy through adulthood; and it can be congenital, or rear its' ugly head later in life. People with ANSD may have normal hearing, or hearing loss ranging from mild to severe; however they always have poor speech discrimination abilities, meaning they have trouble understanding speech clearly. Often, speech discrimination is much worse than would be predicted by the degree of hearing loss as shown on the audiogram, as a person could have near normal thresholds -- or more accurately, "pseudo thresholds," yet still be profoundly deaf. Basically, your child is "hearing" sounds; but because the neural firing from the cochlea has no synchrony, all s/he hears is static. For a truly frightening simulation of what ANSD sounds like to the sufferer, please listen to this sequence of profound, severe, moderate, mild, and then no ANSD samples (window opens into your media player for the WMA file): http://www.kresgelab.com/Resources/AN_simulation.wma Recommended Reading: Multi-site diagnosis and management of 260 patients with Auditory Neuropathy-Dys-synchrony (Auditory Neuropathy Spectrum Disorder), by Berlin, Hood, Morlet et al (2010) http://csd.cbcs.usf.edu/an/Berlin_ANSD.pdf Auditory neuropathy spectrum disorder: Evaluation and management, by Patricia Roush PhD (2008) http://journals.lww.com/thehearingjournal/Fulltext/2008/11000/Auditory_neuropathy_spectrum_disorder__Evaluation.8.aspx [If you are lucky enough to be within driving distance of UNC-Chapel Hill, they have an outstanding ANSD management program] Auditory Neuropathy Spectrum Disorder and Hearing Aids: Rethinking Fitting Strategies (Spirakis 2011) http://archive.hearingreview.com/issues/articles/2011-10_04.asp Management of Individuals with Auditory Neuropathy Spectrum Disorder, by Charles Berlin PhD (2008; Lake Como Conference proceedings) http://www.scribd.com/doc/7843429/Berlin-Lake-Como-Paper-in-Color Interview with Charles Berlin, PhD: Auditory Neuropathy Spectrum Disorder, OAEs, ABR, and More http://www.audiology.org/news/Pages/20120809.aspx My new $25 Auditory Neuropathy/Dys-synchrony Sniffer (Madsen ZS76 Tympanometer) http://thehearingblog.com/archives/723