New S9 auto has a low whistle...is this normal?

We live on a highway so I may need to look at my S9 sounds as white noise and enjoy them....it beats the trucks and motorcycles buzzing by. I may start a thread on that very subject...sound blocking of windows etc...T

Mystery Solved! Or so it seems...tonight will tell. I decided to experiment w/the ramp pressure setting....Last night I didn't use the ramp so my cpap setting was on 9 as the doc prescribed, from the time I layed my head on the pillow. SO....my ramp was set on 6 and I upped the time to 45min to have a better shot at falling asleep before 9 kicks in....Guess what? NO whistles or chirps on exhale at the lower setting. If you are whistling, give it a try w/the lower setting and using ramp. If I recall, the old resmed auto w/cflex had it so that there was no ramp needed if it was set on auto instead of straight cpap. I assume its the same w/the S9? It makes sense anyway that you wouldn't need the ramp if you are already starting out at a low minimum pressure. Correct me if I'm wrong. Hope this discovery helps someone else who hears apap birds singing in their ear at night. Terry

your S9 thinks you are seeeexy!!!hehe

I use the machine with ramp function off and EPR at 1. I still hear the slight whistling, accompanied by Resmed's little Darth Vader sleeping next to me

I still believe S9 is one of the most silent machines out there, but if it's disturbing, you could also try putting it in a cabinet. Have a look at this:
viewtopic/t56198/build-CPAPmachine-in-a ... h-pic.html

No whistles from our machines (S9 Elite and S9 Autoset); but my FX pillows sometimes whistle.
Now that the other hosehead in our bed has an FX, I suppose he'll be getting back at me. . .