Well glad to know it's not just my imagination...but sorry you guys have this, too.

I have sleep apnea and narcolepsy with cataplexy, too, and lately my CPAP machine makes this noise ( at least I've started hearing it anyway) that drives me crazy until my Xyrem kicks in and knocks me out.

Not sure if it did it or not or if it just happened around the same time, but I had withdrawals from Effexor when I was switching to Xyrem, and ever since then my hearing has been hypersensitive. But sometimes sound is distorted...especially voices. The major withdrawal symptom I had was a vibrating electric shock in my head that I could actually hear. I still get it sometimes, especially when I bend over, move my head too quick, or if there's a lot of other noise around...very annoying!