I did check with my DME and they gave me a second Remstar machine that did the same high pitched frequency noise thing after a few hours. My spouse also heard this noise. So they finally gave me a new Resmed Tango that is very quiet though bulky. My DME had never heard of this problem. The whole pur...

Does anyone have any information about a high pitched, intermittent "frequency" noise with the Remstar Series M with C-Flex after several hours of usage? I am new to the machine, and after 4 or 5 hours asleep, I am awakened to this noise (duration approx 10 seconds at a time) and it is dificult to r...