This what Apnea Board member ResMed vice president posted in our old fourm:
At ResMed, we believe everyone that needs CPAP is entitled to a quiet machine. Ultimately, you can/should take a noisy device in to your HME, but before you get to that step there may be a few things you can do on your own at home to eliminate the sounds.
The most common whistling or other high pitched sounds are caused by small leaks which allow air to escape. In many cases sounds like these are caused by mask fit, sticky mask valves, or loose connections. Another common cause is dust that has entered the device. Before returning the unit to your HME, please take these steps - they may help in the diagnostic process and in many cases allow you to solve the issue.
* Remove the dust filter from the back of the flow generator. Check for damage or clogging – Both conditions can cause noises. Replace if necessary. If there is a small amount of dust that is causing the noise, it will likely work it's way through if the filter is replaced.
* While fully awake, disconnect the tubing from the machine and place the mask on your face. Disconnect the tubing from the mask inspect the surface for scratches or other physical deformities. Reconnect the tubing to your mask and make sure the tubing is firmly connected to the mask inlet (no play or rotation on the fitting) and breathe normally. Do you hear the sound (even very faintly, as sounds feel amplified when fully connected and ready for bed)?
- If so, please wash the mask and tubing very thoroughly in warm water, then allow to air dry and repeat the test. In many cases a slightly sticky valve in the mask assembly will cause a whistling sound.
- If available, repeating the test with a different mask may be helpful since this will give you multiple sounds to compare and help detect/isolate any whistling.
* With your machine set up for a regular night of sleep (and all connections checked for tightness), place the mask on your face and turn the machine on. Now complete a slow breathing cycle: inhale, pause (with lungs inflated) for 1-2 seconds, exhale, pause (with lungs deflated) for 1-2 seconds. Repeat the process a few times, taking note of any sounds. Now breathe normally. Do you hear the whistling sounds? Did the sounds change and become evident at a particular point in the breathing cycle.
- If the sound only appears in the pauses during the breathing cycle and you have verified all connections are secure, please take the unit in to your DME for evaluation.
- If the sounds only appears one specific portion of the breathing cycle, it is more likely that you have a small leak. Reposition the mask on your face or tighten slightly, as appropriate (home mask fitting/adjustment instructional videos can be found on the right side of this page from our YouTube channel, http://www.youtube.com/user/ResMedAmeric...FAF5627F3F
- After adjusting your mask fit, repeat the test while hooked up to your machine. If you still hear a pronounced sound, please take the unit in to your DME for evaluation.
If all this fails, please take the device back to your HME. ResMed has a 2 year guarantee on all flow generators sold in the US
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