I put mine on something soft so the hard night stand does amplify everything.
I run a fan (for the dog) and that pretty much wipes out any sound in the room. I'm over due for a new tub.
Using FlashAir W-03 SD card in machine. Access through wifi with FlashPAP or Sleep Master utilities.
I wanted to learn Binary so I enrolled in Binary 101. I seemed to have missed the first four courses.
I haven't been able to replace the machine. But, did get the humidifier chamber replaced which helped with the squealing, whistling, and hip-hop disc scratch noises.
Sadly, the chirring sound is still very loud. This is even with ear plugs, a blanket on surface it sits on, a folded blanket underneath the machine on top of the surface blanket, a cotton bath mat folded over the machine, (but the air vent left undraped) and a towel tri-folded and wrapped around the tubing on the rear side.
I am extremely sleep deprived, have lost income, and am on shaky ground employment wise due to the negative side effects of the CPAP. I've been using it faithfully since July 2015.
Sorry to be such a downer. But, honestly I'm not seeing the good here overall. Maybe my heart is happier, but that does not matter if you loose your job and cannot function in the world due to sleep deprivation from the machine noise.