Hi there - I found 1 study showing that RSD affects hearing - I'm sure there are more studies out there, but this is the most recent one I could find.

Hyperacusis in patients with complex regional pain syndrome related dystonia, de Klaver,M.J.M.; van Rijn,M.A.; Marinus,J.; Soede,W.; de Laat,J.A.P.M.; van Hilten,J.J. Journal of Neurology, Neurosurgery, and Psychiatry. http://jnnp.bmj.com/cgi/content/abst....2006.111609v1 Published Online First: 30 April 2007. To whom correspondence should be addressed. E-mail: j.j.van_hilten.neurology@lumc.nl.

This study describes how people with CRPS are acutely sensitive by loud noise. (frogga wears earmuffs so she's certainly an expert on hearing hyper-sensitivity!)

If RSD can affect hearing in one extreme, I wonder if it could affect it inthe other direction as well (hearing loss)? For example, RSD can make skin extremely sensitive, but after RSD has progressed past into a more severe phase it can make your skin so it doesn't feel anything... like something burning. I wonder if it can do that to the part of the brain that is supposed to register sound?
Maybe Somebody Brave could email the researcher and ask?!