New member, S9 noise (detailed).

[Dave_NY]

Hello everyone, this is my first post here, so let me introduce myself: I have been successfully using CPAP for roughly five years (Resmed S7 at 8.6cm and passive humidifier). I "took to it" very easily with few problems and very good compliance.

The S7 served me well, but is not particularly svelte, good looking, or feature rich... It took up lots of room in my luggage and I never traveled with the giant passive humidifier (which I only used occasionally at home anyway). It seemed to me that with 14,000 hours on the clock, the S7 was starting to get somewhat noisier in use.

Two weeks ago, I purchased as S9 Elite with humidifier to address the issues detailed above. I was also hoping to get Rescan software for detailed analysis, but it is no longer available to the consumer. Everything about the unit is a huge step-up from the S7 (size, features, "feel" in use, and appearance). I've traveled with it already, and was able to pack both the S9 and humidifier in less space than the S7 alone.

Now - On to the reason for this post:

Unfortunately, I was immediately surprised with how much noise the unit made in use. The sound of rushing air is very apparent with each breath. I feel like Darth Vader because each breath is amplified at the unit. However, the unit is very quiet at the mask. I removed the humidifier and connected directly to the S9 unit and determined that the noise originates in the S9 unit itself, not the humidifier. I also tried re-seating and removing the filter to no effect.

I think I've convinced myself that I have a faulty unit and need to contact my vendor for a replacement (bought online), but I wanted the opinion of the experienced users here before I do that. I don't want to saddle the vendor or Resmed with unnecessary costs if the noise is typical.

Prior to the purchase, I read comments like "we can hardly tell if the unit is even turned on". So, today I did some comparison testing to try to figure out if there is a real issue or not. My wife and I compared the S7 to the S9, one at a time, with each unit sitting in the same location. Results follow:

Mask on, no flow (exhale or hold breath): At the unit - Old S7 very slightly louder than S9 (although the S9 does make a slight "wheeze"). At the mask - Old S7 noticeably louder than the S9 (because EPR reduced flow?)

Mask on, inhaling (here's the bad part): At the unit - Old S7 significantly quieter than the S9. The S9 makes significant "rushing air" noise which gets louder with deeper breathing (higher flow rate).

Mask off, open flow: Old S7 - no increase in noise at the unit, moderate noise at the mask. S9 - Loud at the mask and just as loud at the unit.

Finally, the units are rated for noise levels in to 30 db range but I don't have the facility to measure that low, and, I don't know what the full test parameters are. However, I do have an SPL meter that measures from 50 db up. Using that, I find the following:

Old S7, open flow: At the unit - Too quiet to register within 6 inches of the unit (<50 db). At the open hose - Maybe in the 40's from twelve inches away? The needle is just off the seat, but below 50 db.

New S9, open flow: At the unit - 53 db from 12 inches away (subjectively much louder than the S7). At the open hose - 58 db from 12 inches away (subjectively louder than the S7).

If you've read this far, thanks for sticking with it.

Dave

[jmelby]

I have found the S9 to be extremely quiet... some have reported hearing a faint whistling sound on exhale, but I have not noticed this (maybe related to EPR since I don't use that). In any case, it sound like you either have a defective unit or a leak somewhere in your system... have you checked the hose thoroughly and/or tried a different hose to see? What about the humidifier door... sometimes you need to manually move the door latch to get it closed tightly? If all else looks good, I would agree that you have a defective unit.

[Dave_NY]

... have you checked the hose thoroughly and/or tried a different hose to see? What about the humidifier door... sometimes you need to manually move the door latch to get it closed tightly?

I considered that too. The hose is in good condition and I removed the humidifier and connected directly to the S9. It made no difference.

[valmet49]

Thanks for the technical evaluation of the S9. I have just switched over to ResMed S8 Vpap 25 after logging 9500 hours on a Resperonics auto bipap pro. Like you, the Resperonics tank that has served me well was feeling the effect of age so it was time to update. My DME (as my request) gave me a new Resperonics M bipap auto. I like the machine size and the fact it didn't have a 4 pound brick power supply.

Using it... as compared to the trusty bipap pro the new M model has a really loud air flow sound... like, as you said, Darth Vader. No way I can sleep with this noise. Closer examination of the Resperonics M humidifier tank shows a convoluted and fairly long square air passage design with sharp corners. Essentially the sharp corners create turbulence and long air passages amplify the noise. Basically a speaker system. The old Respronics Pro has smooth rounded humidifier air passages that are short. So less turbulence and noise.

Ok... I contact my DME and return the Resperonics M and they supply me with a ResMed S8 to try out. The S8 is about 40% quieter than the Respronics M but still louder than the old Resperonics Pro. The S8, like the Resperonics M has a convoluted air passage humidifier tank design with a square machine air output port. Without the heater/humidifier unit the S8 is quieter although not great.

[scrapper]

pm sent..........

[JStaggie]

I've had no similar issues with my S9. Whether inhaling or exhaling, the S9 is essentially silent. There a times when I hear breathing at the mask, but often even the mask is so quiet I've pulled it off enough to break the seal so that the airflow confirms that the unit is working. I have not, however, used the S9 with the slimline hose that connects directly to the CPAP, instead using the humidifier with the climateline hose.

[AirBreather]

I upgraded from a ResMed S8 to S9 five days ago. Prior to the S8 I used a REMstar Pro C-Flex CPAP and a variety of other machines dating back 17 years. The noise made by CPAP machines years ago resembled a vacuum cleaner more than they resembled the noise from any modern machine, so all the new machines seem very quiet to me.

My S8 was on the floor underneath a night stand. I couldn't hear it at all and could only tell whether it was running by feeling exhaust air from the mask. My new S9 is on top of the nightstand at the height of my head despite this warning in the Clinical Manual "Always place the H5i on a level surface below the level of the user to prevent the mask and tubing from filling with water." I can hear it slightly, but the sound level is so low compared to machines I have used in the past that it doesn't disturb me.

[Dave_NY]

velmet49: Your experience is not encouraging, I am still hoping the "Darth Vader" effect is a flaw in my machine. I have a hard time believing that others are not bothered by this, and instead, comment on how silent the machine is. However, this is the reason for my post, to see if my expectations are wrong.

AirBreather and JStaggie: This is more in line with my expectations. I do not consider my S9 "essentially silent".

Dave

[Nord]

Hi Dave

I have used the S9 with EPR engaged and SlimLine for 10 days and now ClimateLine with EPR and I find they are equally quiet. They are so quiet that my wife says she cannot tell if I have it running.

I have only compared to M Series Respironics and C-Flex set to 2. The Respironics sounded like Darth Vader and either kept me awake or woke me up. I kept it under the bed on the floor with some sound deadeners.

Perhaps it is the machine because your numbers at 1 foot are significantly different than ResMed reports and many others have found. I would have the DME bring another machine around and make the comparison yourself... maybe even to some others. You need to convince yourself.

Nord

[DreamDiver]

I did an audio comparison with my old machine. Consider doing the same. It might give you some ammunition to prove it's messed up. I'm guessing your machine should be replaced. It really should be very quiet.

Edit: Sorry - I now see you've already done the comparison. Send it back for sure.

[Dave_NY]

I did an audio comparison with my old machine.

DreamDiver: I listened to your samples. It sounds like your machine is slightly noisier on the exhale while my unit makes considerably more noise on the inhale when the pump is moving more air.

From the replies I'm seeing, I think I should give my vendor a call and discuss with them. I'm actually a pretty good sleeper (except for the whole Apnea thing...) and relatively immune to noises and distractions. So, if I think it's too loud...

[DreamDiver]

I did an audio comparison with my old machine.

DreamDiver: I listened to your samples. It sounds like your machine is slightly noisier on the exhale while my unit makes considerably more noise on the inhale when the pump is moving more air.

From the replies I'm seeing, I think I should give my vendor a call and discuss with them. I'm actually a pretty good sleeper (except for the whole Apnea thing...) and relatively immune to noises and distractions. So, if I think it's too loud...

Well, if you're going to get a new one, you might as well make it an S9 Autoset instead.

[JStaggie]

Any update on this? Curious because for the last 3 nights my previously silent S9 appears tohave the same problem. Every breath is amplified at the base. It absolutely didnot sound like this before. I don't know what happened.

It's not loud enough that it's keeping me awake, but it does seem to be getting worse.

[blakepro]

Any update on this? Curious because for the last 3 nights my previously silent S9 appears tohave the same problem. Every breath is amplified at the base. It absolutely didnot sound like this before. I don't know what happened.

It's not loud enough that it's keeping me awake, but it does seem to be getting worse.

Its concerning that comments like this are starting to pop up. I wonder if there is a defect in the S9 that manifests under certain conditions.

It might help if everyone posts their pressure settings too since I suspect that would have a big impact on the amount of noise.

[JStaggie]

In my case, it's running in APAP mode with a 4-12 pressure range. I'm mostly concerned because I've traveled with it and just got back from a trip Friday and wonder if I bumped it or something. It isn't as loud as the first poster mentioned,but I don't recall noticing any sound when I inhaled.

Then again, it's possible that I only noticed it after the post mentioned the noise. I doubt that though because I was truly amazed by how silent it was before.