At night, as I breathe, the machine makes a weird whistling or humming noise (very tonal), but only as I'm breathing in. If I hold my breath or breathe out, the machine is essentially silent (making only a light whooshing noise).
This of course makes it very hard to sleep.
This has only started happening recently, but I'm not sure precisely when. I've noticed for a while that I would get these kinds of whistling/humming noises as the machine was ramping up -- again, with different notes as I breathed in and out, and shifting as the pressure ramped up -- but it was quiet once it was at full pressure.
One item of note is that I recently (within the last month) switched from using nasal pillows to using an over-the-nose mask. I'm not positive the problem occurred precisely when I changed, though, since I usually sleep with a white noise machine running. I first noticed it when I was traveling, and didn't have the white noise machine, but now it's pretty noticeable. (It's also possible that the CPAP got damaged while I was traveling)
Is this problem:
- Something I can fix?
- Something broken in my CPAP, so I should get it replaced if I can?
- A known problem with this model of CPAP?
Any information would be very helpful.