ResMed S9 whistle problem - Solutions?

[Sleepster]

After reading this thread the other day I payed attention .. Seems My res med s makes WAY more whistle when the water chamber is FULL , not much at all when almost empty and only on Exhale. Go figgure?

This could be a hint. Anybody notice a difference in pitch with the level of the water tank?

[jgjones1972]

After reading this thread the other day I payed attention .. Seems My res med s makes WAY more whistle when the water chamber is FULL , not much at all when almost empty and only on Exhale. Go figgure?

This could be a hint. Anybody notice a difference in pitch with the level of the water tank?

After reading this I checked it out:

With any one particular mask the whistling was the worst with the H5i disconnected and the hose connected directly to the S9 or with the H5i connected and the water chamber filled to the max line (or actually just a tiny bit above it, where I normally fill it to). There might have been a little difference between these two, but not enough to tell by just listening.

With any one particular mask the whisling was least noticeable with the H5i connected but empty.


Worst whistling was with nasal pillows and hose connected directly to S9, or nasal pillows and hose connected to H5i with full tank.

Whistling was least noticeable (not noticeable at all to me even when exhaling hard) with full face mask and hose connected to empty H5i.


Whistling was still coming from inside S9 unit and not from the H5i.



All of this seems to suggest (with my extremely limited knowledge on these things) that it is coming from the flow generator and has to do with flow resistance.

It seems to have consistently held that the more room I introduce into the system (i.e. higher volume of air between the flow generator and my lungs), the less whistling I get. The more I tighten the system up - less air space (i.e. less air to compress on exhale) the more whistling I get.


I wish I had a larger diameter hose like a standard hose (NOT SlimLine) or a ClimateLine Max to check. I might just order one (standard full size hose) to find out.

It would be nice if some others would try the full/empty water chamber thing and/or standard/slim hose (if you have 'em).

[Shastzi]

I will try adding a 9ft long hose extension on. That might do something.

[Sleepster]

This suggests to me that the small chamber consisting of the space between the flow generator and the hose is resonating with the pitch of the whistle. When you increase the volume of that chamber you lower that resonant frequency making the whistling noise less noticeable.

[woody109]

Paula
My machine serial number start with 2210

22= country of manufacture: Australia (23 Singapore)
10= year of manufacture: 2010

I'm researching the RESMED S9 whistle on exhale and this is my first post just to add a "Me Too". I've been using a CPAP for over 5 years, the first being an S8. The S9 Elite whistle is definitely coming from the unit and not the humidifier or the hose or mask. I've tried all the suggestions I've found to eliminate the whistle with no luck.

The whistle occurs with or without the humidifier and is louder with a soft exhale. I have found that I can actually modulate the whistle by varying the exhale.

For data gathering, my serial number starts with 2312.

[jbernardk]

I am having this problem too. Usually does not happen at first but when I wake up later it is very noticeable.

[cowboy1970]

I also get this. It is very mild and doesn't keep me from falling asleep.

I also notice it only happens on exhale. Not sure if water tank level affects the pitch of the whistle.

I have been having dreams that the little people have put the 'come hither' on me and the cry of the banshee is drawing me to them.

...but again, this could be just residual effects left over from the Ambien. OR I shouldn't eat Tillamook Peanut butter and chocolate ice cream while watching Darby O'Gill and the Little People right before bedtime. ya, you're right, it's that darn Ambien!

[Airstream]

I also get this. It is very mild and doesn't keep me from falling asleep.

I also notice it only happens on exhale. Not sure if water tank level affects the pitch of the whistle.

I have been having dreams that the little people have put the 'come hither' on me and the cry of the banshee is drawing me to them.

...but again, this could be just residual effects left over from the Ambien. OR I shouldn't eat Tillamook Peanut butter and chocolate ice cream while watching Darby O'Gill and the Little People right before bedtime. ya, you're right, it's that darn Ambien!

Cowboy, a little off the subject, but what model mask is depicted in your avatar? I think I had one like that (bad memories), or maybe it's just that it looks like the sore on the bridge of my nose. Hope it (your avatar) doesn't scare away any new CPAP users. Jeff.

[SuperSleeper]

It's the new Klingon CPAP Mask.

[Shastzi]

Ah, I see. I thought it was the new Face Hugger Alien model.