Janknitz wrote:...so it might be worth trying out a ResMed S9 to see if you have the same problem or not--if you have access to one for a trial period.
Unfortunately I've already tried an S9 (see my "LORD HELP ME rant" a few messages up). It was the first new machine I tried since I was currently using a RESMED S7 and wanted to stick with the brand.
Couldn't believe how small and high-tech the thing was! Was all excited until the first night I used it. Every exhale produced a little "chirp" sound.
Before I even had a chance to ask my wife if she heard it she told me she was hearing a strange noise...
I went online and found numerous other posts about people hearing this noise as well. I stuck the S9 in a closet for 3 months and went back to the S7.
I recently dug it back out again and checked online hoping for a new resolution in the months that had transpired, but no go...just more posts about the same thing.
I compiled a cut-and-paste list of at least 25 different posts from people describing the problem so I could have some ammo when I went to Resmed.
After talking to my DME, he checked with Resmed and they said they were unaware of this issue...no surprise there.
I returned the S9 before I ever had a chance to use it long enough to experience any other issues, like pulses or what-not.
I got a F&P Icon next - LOVED it, but it "whistled" noticeably on every exhale...tried another one, same issue so they are made that way.
In both of these cases, the noise was only noticeable after going above 11 or so cm - below that it was not NEARLY as noticeable...I run at 14
I guess maybe the majority of people use lower settings than I do so this isn't a big enough deal for these companies to look into.
The REMstar auto is very quiet - it doesn't have a problem being quiet at higher settings...but I just can't fall asleep with it.
Oh well! I will see if anyone else can verify whether or not the 'M' series does anything fancy with the pressure while in straight CPAP mode and go from there...
Thanks again to everyone for the help!
-Greg