A student that I worked with over the summer has recently been diagnosed as having auditory neuropathy/dys-synchrony. While initially, I had an idea of what that likely consisted of, I wasn't totally clear on the facts. So, while trying to research a little about this condition, I came upon this link (http://www.babyhearing.org/hearingamplification/causes/neuropathy.asp) and the site contained some good information. It also provided links to additional sites that were helpful. Things I was surprised to learn about AN: 1. Severity can fluctuate from day to day and even hour to hour 2. The most common diagnostic tools are Auditory Brainstem Response (ABR) and Otoacoustic Emission (OAE) 3. The main differences between auditory processing disorder and AN are that AN presents with abnormal or absent middle ear muscle reflexes and ABR, while these are normal in auditory processing disorders.
If you're interested in this topic, be sure to click on the acoustic simulations link at this website: http://auditoryneuropathy.tripod.com/ANindex.html, it's absolutely mind boggling. Another good site that was thorough in differentiating between APD and AN is: http://www.otometrics.com/insights_june_2007_print.pdf.