Res Med S9 exhale noise

[JTE48]

I've used an S8 for 5 years and recently switched to an S9. I like it but on exhale there is a distinct sound coming from the unit. If I remove the humidifier and climate tubing (using just the S9 unit with standard tubing) it's slightly worse. I've read some related posts about the issue on this forum and others. It's definitely not my mask (full quattro mirage) - sound is coming from the unit. Hose was tight too. Has anyone figured out what this annoying sound was from? S8 never had this weird sound. Thanks.

[avi123]

If you use EPR then this could cause noise on exhale b/c it affects the inside blower.

[Pugsy]

No, we never figured out what to do about the S9 exhale noise. Some people hear it and some people don't.
I discovered that if I don't exhale as forcefully that the noise is greatly reduced.
I tried playing with EPR and different hoses without any luck figuring out how to make it totally go away. We have a big thread on the noise on the forum in the past. You can do a forum search for "S9 bird calls" and find it if you haven't already.

For some people the noise is a deal breaker but most of us that hear it just get use to it and eventually it is like white noise in the back ground and the brain sort of tunes it out.

[JTE48]

my unit sits at bed level on a table next to me so I can switch it off easily. It makes the noise whether EPR is on or off. I think I will call the tech at ResMed and chat with him more about the issue since I've done some elimination testing of my own. Maybe it would be worth it to chat with ResMed in Australia too since that is where the units are made.

[newpapper]

My S9 was made in Singapore.

[jabman]

I use the s9 and even though I can hear something when I exhale, I always assumed it was from exhaling. This is the machine I started on. My wife sleeps with a fan on low, the fan drowns out the exhale noise. Maybe I'm not hearing what you are though.

[Bobby269]

I noticed that on my unit. The Va gave me a new unit at my last check up. This one is so quiet. You can barely hear any noise at all.
Resmed will give you a free estimate on the cost of repair. You have to have a DME send it back for repair.

[JTE48]

this unit is a week old so I'll just send it back I think.

Edit: just chatted with a ResMed tech in California (a different one this time). It appears the exhaust sound is inherit in the design of the S9. I'm thinking this is something we just have to get use to or switch to another model. In my case, I like the S9's quick pressure response to airway blockage over the S8. The tech suggested putting a towel over the unit careful not to block the intake. Will try that and see how it goes. Like others have pointed out . . . might be something I just get use to with time. Thanks everyone for your feedback.

[Robespierre]

The S9 seems to have that exhale noise if the humidifier reservoir is filled even a little too much. I've found that if it's just filled barely to the line, it's noticeably quieter.

[jabman]

The S9 seems to have that exhale noise if the humidifier reservoir is filled even a little too much. I've found that if it's just filled barely to the line, it's noticeably quieter.

I don't have a problem with filling my humidifier to the line but if i go over even a little bit then I get a bubbly sound and water in the hose.