new odd noise - AirSense 10 & AirTouch F20

I've been using the AirSense 10 AutoSet for years. Last December I moved to the AirTouch F20 Foam Full Face mask due to noise from the nasal pillows and the change was amazing. However, since then, every now and then - with no obvious pattern, there is, for lack of a better word, a "flapping noise" (it's exactly one flap) exactly at the point moving from inhale to exhale. it's hard to tell if it's from inside the machine or from the vent (there do seem to be some flaps inside that...maybe?).

this is not a "wheezing" sound that other's have spoken about.

two nights ago my wife moved the machine a bit and it stopped. and it came back last night. mostly I sleep through it, it does however bother my wife. Last night she noticed it about 130am; my stats from last night were good (AHI .89) and absolutely nothing going on at that time.

I do notice that the connection between the hose and the mask seems to have a couple of flaps - maybe... could that be it? I've been using this unit since early December. Also I can't remember the last time I cleaned the vent...?

I'm going to use a new mask, cushion & vent tonight.

My settings are:

Mode APAP
Pressure Min 8.00 cmH2O
Pressure Max 11.60 cmH2O
Antibacterial Filter No
Climate Control Auto
EPR Full Time
EPR Level 3 cmH2O
Essentials On
Humidifier Status On
Humidity Level 4
Mask Full Face
Ramp On
Ramp Pressure 4.00 cmH2O
Ramp Time 10.00 Minutes
Smart Start On
Temperature 27 ºC
Temperature Enable 2

Thanks! This forum has helped me many times over the years.

jim.evo wrote: ↑

Fri Mar 19, 2021 12:04 pm

it's hard to tell if it's from inside the machine or from the vent (there do seem to be some flaps inside that...maybe?).

In the elbow that is between the mask and the hose, there is an anti-asphyxia valve. This valve is in the form of two small flaps. These flaps are closed by the pressure in the CPAP loop during the normal use of the CPAP process. Should power to the machine fail, the flaps open to allow the user to breathe through the valve.

It's possible, but not likely, that during a forceful breath, the flaps would open and close causing a noise. This would also happen if your machine lost power and then restarted. Of course, this is just one thing that could cause the noise. Have you developed a habit of cracking your knuckles during sleep?

The AA valve on some masks also may get into the wrong position,
and may make more noise when hung up.

a new valve has done the trick! thanks everyone for your replies.