How many decibels is a CPAP machine?
A CPAP machine declares between 25 and 31 dBA of sound pressure in the ISO 80601-2-70 test figures we found, each with an uncertainty of 2 dBA. Home units with a side cover sit at the bottom of that range, and travel units at the top.
Here is what each maker declares, sound pressure first:
- ResMed AirSense 11: 25 dBA with the side cover, 27 dBA with the HumidAir 11 tub
- ResMed AirSense 10: 25 dBA with the side cover, 27 dBA with humidification
- ResMed AirMini: 29 dBA
- Transcend Micro 510 and Micro: 31 dBA at 10 cm H2O
ResMed's guides do not say which pressure the machine was set to during the test. Transcend's manuals do, and the Micro 510 manual adds that the test runs with no mask connected and microphones placed in a circle around the device.
Sound power is a separate column: 33 and 35 dBA for the AirSense machines, 37 for the AirMini and 39 for the Transcend units. We list it beside each machine and never rank it against sound pressure; our sound power vs sound pressure page sets out what separates the two.
For where 25 to 31 dBA sits beside a whisper or a refrigerator, see our decibel chart.
Is the AirSense 11 quieter than the AirSense 10?
No, the AirSense 11 is not quieter than the AirSense 10 on paper: ResMed declares 25 dBA with the side cover and 27 dBA with the humidifier for both, and the same 33 and 35 dBA sound power.
The AirSense 11 guide for the Americas cites ISO 80601-2-70:2015. ResMed's newest AirSense 10 guide, a June 2026 European edition, cites the 2020 revision and adds ISO 80601-2-74:2021 for the humidifier. The ANZ guide for the AirSense 11 also uses the 2020 edition and prints identical numbers, so the revision change did not move ResMed's figures.
The choice between them comes down to features and what an equipment provider offers, and no decibel separates them. Both guides cover three models: AutoSet, Elite and the fixed-pressure CPAP. The AutoSet for Her appears in both as well.
Is a travel CPAP louder than a home CPAP?
Yes, both travel CPAP machines here declare more sound pressure than ResMed's home units: the AirMini declares 29 dBA and the Transcend Micro 510 31 dBA, against 27 dBA for an AirSense with its water tub.
ResMed puts this on its own UK shop page for the AirMini, which says the travel device "has a higher sound level compared with Resmed home devices (29dBA compared with 27dBA for home devices)".
Between the two travel units, the AirMini's 29 dBA is 2 below the Transcend's 31, and both carry an uncertainty of 2 dBA. The Transcend weighs 0.49 lbs to the AirMini's 10.6 oz, and can run from Transcend's optional PowerAway battery.
The 27 dBA on Transcend's home page
Transcend's home page advertises "Just 27 dBA with the included WhisperSoft Muffler". The Micro 510 manual explains where that number comes from: an "internal acoustic test method derived from the general test principles described in ISO 80601-2-70", which it says is "not part of ISO 80601-2-70 conformity assessment".
That figure cannot sit beside ResMed's ISO figures, so we rank the Transcend on its 31 dBA. The manual is unusually frank that standard test figures "do not represent the sound levels a user will experience during sleep", because mask, fit, leak and distance all change what reaches the pillow.
Does a humidifier make a CPAP machine louder?
Yes, a water humidifier adds about 2 dBA to ResMed's declared figures: 25 dBA with the side cover becomes 27 dBA with the HumidAir 11 tub half filled, on the same ISO test.
The pattern holds across makers who split the figure. Philips's manual for the first DreamStation, which predates the DreamStation 2, declared 26.1 dB(A) for the device alone and 27.3 dB(A) with its humidifier. ResMed's AirSense 10 guide shows the same 2 dBA step as the AirSense 11.
Whether to run a humidifier is a therapy question, and the prescribing clinician or equipment provider settles it. For noise, the side cover figure is the one to read if the tub stays off. Our humidifier guide covers room humidifiers, a separate machine.
Is the noise coming from the CPAP machine or the mask?
A CPAP machine and its mask both make noise, and ResMed's AirMini guide alone declares them apart: 29 dBA for the device under ISO 80601-2-70, and 15 to 19 dBA for the mask vent under ISO 17510:2015.
The mask figures depend on the connector. The AirMini guide gives 19 dBA with the F20 full face setup and 15 dBA with the N20 nasal or P10 pillows setup, each with an uncertainty of 3 dBA. Those are exhaust vent figures, measured with tubing and mask fitted, so they are not added to or ranked against the machine figure.
For air leaking around the mask, the AirSense 11 guide points to the mask's own fitting instructions and the machine's Mask Fit function, and the equipment provider who set the machine up can help with the rest. Our quiet and sleep modes explainer covers the night settings other bedroom appliances use.
Yes, but React Health and BMC frame their CPAP figures as limits, so neither sits in the ranked group. React Health's LG3600 manual says the Luna G3's levels "shall not exceed" 28 dB(A) sound pressure and 36 dB(A) sound power at 10 hPa.
That table cites ISO 4871 for the dual-number format and names no test standard, and React Health's product page shortens it to under 28 dB. BMC Medical, which builds the Luna G3, promises "noise performance under 28 dB(A)" for its G3 series and lists under 30 dB at 10 hPa for its M1 Mini travel unit.
A not-to-exceed level is a ceiling, and a ceiling does not tell you where the machine actually measured. The FDA also lists a Class 1 recall, Z-2979-2026, for 20,160 Luna G3 APAP units identified by serial number.
Can you still buy a Philips DreamStation 2 or a Fisher & Paykel SleepStyle?
No, neither can be bought new from its maker in the US in October 2026. Philips stopped selling new CPAP machines here under an April 2024 consent decree, and Fisher & Paykel says it is no longer selling the SleepStyle in the United States.
The FDA says the decree restricts the sale of new Philips Respironics CPAP and BiPAP machines "until certain requirements are met", and Philips's May 2026 FAQ still describes those terms. Separately, in November 2023 the FDA asked users to carefully monitor DreamStation 2 machines for signs of overheating.
Both makers did print figures. Philips's 2022 DreamStation 2 manual declares 27 dB(A) sound pressure and 35 dB(A) sound power, and Fisher & Paykel's SleepStyle sheet lists "28.0 ± 1.5 dBA" with no test standard. Both machines are under also considered.
Can you buy a CPAP machine without a prescription?
No, a CPAP machine is a prescription device in the US. ResMed's AirSense 11 guide says federal law restricts it to "sale by or on the order of a physician", and Transcend's manual says the same for the Micro 510.
The prescription also sets the pressure, the mode and any humidity. This page compares declared noise only and does not suggest settings. The safety points we cite come from the FDA and the makers' manuals, and the manual for any machine, along with the clinician who prescribed it, outranks anything written here.
