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[CPAP] What are your dB levels using phone app? My Dreamstation result - Printable Version

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What are your dB levels using phone app? My Dreamstation result - sleepyl - 01-29-2019

I ordered a Dreamstation on Dec 6 2018 from CPAPoutlet Commercial Link Removed after having a "free trial" of the same machine.  The trial machine seemed almost silent, but I didn't get dB levels on it.  I recieved the new machine Dec 22, and the first night I had it I found it extremely noisy.   There was a whirring sound which changed pitch as I breathed.  I tried moving it, covering it with pillows, etc. but I asked immediately for an RMA.   It took almost a month, but I got my replacement yesterday and it seems much quieter.

I downloaded Sound Meter - Decibel meter & Noise Meter for android by Tools Dev.   I put my phone on top of the machine,  and breathed through the mask for a couple of minures.   Here's my results:

The noisy machine was 53 dB min, 57 dB avg, 63 dB max

The new machine is 42 dB min, 53 dB Avg, 61 dB max -- I still think it is louder than the machine I had for the free trial.

I am wondering if anyone else has measured their machine with an app, and, if so, what are your results (please include your machine type).

Thanks!






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RE: What are your dB levels using phone app? My Dreamstation result - Fats Drywaller - 01-29-2019

Just an observation:  If you want to be able to compare your numbers to the ones published by the manufacturers, it'd be good to use the distance from the machine that was used in those measurements.  I don't know what that distance is, but it should be specified in the ISO standard.

From the Dreamstation manual:
Quote:Declared Dual-Number Noise Emissions Values In accordance with ISO 4871

The A-weighted sound pressure level is:
Device:  26.1 dB(A) with and uncertainty of 2 dB(A).
Device with Humidifier:  27.3 dB(A) with and uncertainty of 2 dB(A).

The A-weighted sound power level is:
Device:  34.1 dB(A) with an uncertainty of 2 dB(A).
Device with Humidifier:  35.3 dB(A) with an uncertainty of 2 dB(A).

Note: Values determined according to noise test code given in ISO 80601-2-70:2015, using the basic standards ISO 3744 and ISO 4871.

Resmed Airsense 10:
Quote:Sound:
Pressure level measured according to ISO 80601-2-70:2015 (CPAP mode):
SlimLine: 25 dBA with uncertainty of 2 dBA
Standard: 25 dBA with uncertainty of 2 dBA
SlimLine or Standard and humidification: 27 dBA with uncertainty of 2 dBA

Power level measured according to ISO 80601-2-70:2015 (CPAP mode):
SlimLine: 33 dBA with uncertainty of 2 dBA
Standard:  33 dBA with uncertainty of 2 dBA
SlimLine or Standard and humidification: 35 dBA with uncertainty of 2 dBA

Declared dual-number noise emission values in accordance with ISO 4871:1996.



RE: What are your dB levels using phone app? My Dreamstation result - sleepyl - 01-29-2019

Good point, I'll check ISO 4871  Thanks


RE: What are your dB levels using phone app? My Dreamstation result - sleepyl - 01-29-2019

So if you search on some info on dB vs DBA, there is some interesting information out there. I've learned a lot this morning. I can't find the actual spec, but most are saying that the measurement is taken from where a listener would logically be for that equipment, or 1 meter away as a more general rule. One site interestingly says "Pro audio equipment often lists an A-weighted noise spec − not because it correlates well with our hearing − but because it can "hide" nasty hum components that make for bad noise specs. Words to bright minds: Always wonder what a manufacturer is hiding when they use A-weighting. "

However, in order to compare apples to apples, I am curious what other people get as a dB level when using an app and putting their cell phone on top of the CPAP machine.


RE: What are your dB levels using phone app? My Dreamstation result - Fats Drywaller - 01-29-2019

Yes, one meter, thanks.

I searched for more just from casual curiosity, and found this, which is TMI for most folks including me and has a comprehensive "Appendix A: Determination of Noise Level in accordance with ISO 80601-2-70:2015-01" so will be of interest to those who do want to get all technical about it.  ISO 80601-2-70 is the one that's specifically about CPAP equipment rather than audio.

http://www.artp.org.uk/download.cfm/docid/8181E52B-BE02-43EC-AB66C56CCE8F7737

(.org.uk is non-commercial, of course)

"Association for Respiratory Technology & Physiology: ARTP Standards of Care: CPAP Devices (Technical and Performance)" (PDF, 40 pages; Appendix A is 6 pages)

Quote:... The acceptable noise range (Sound Pressure Level) will be <30dB at 10 hPa/cmH2O at a distance of 1 metre (independent, standardised assessment conditions).  Manufacturers in their technical specifications should quote noise measured according to EN ISO 80601-2-70:2015.  Conducted noise can be quoted in addition.  Noise must be ascertained by independent laboratory testing according to the protocol specified in Appendix A.