Sleep Apnea Support Group
Sleep apnea is a common sleep disorder characterized by brief interruptions of breathing during sleep. People with sleep apnea partially awaken as they struggle to breathe, but in the morning they may not be aware of sleep disturbances.
http://www.healthcareasia.org/2018/when-breathing-too-much-can-kill-you/
When breathing too much can “kill” you
Pull it out and close it again and then shove it back into the machine
There also may be a problem with the ClimateLine tubing.
Pull it out from the back and then replace it again
This usually takes care of any whistling.