@Neuropyramidal Pease, Mr. Scientist, can you help me? Or maybe this has to remain one of life's mysteries? I tried to go to sleep long ago, but it turned into the episode on Breaking Bad where Walter White was being driven insane by a fly.

My previous C-PAP started making Doppler effect noises. EEEEEEEEEEEE when I breathed in and a lower AAAAAAAAAAAAAAA when I breathed out. It was the motor, it was under warranty, I got a new one.

New C-PAP machine. It is silent, but when I breathed out there was a rattling noise in another corner of the room. After much sleepy rummaging around, I finally figured out the tower air conditioner was rattling every time I breathed out. They are both plugged into the same 5-plug adapter, and of course the air conditioner is OFF. So, WTH????? That's what I most want to know.

All four things plugged into the adapter made a tight connection (as did the adapter itself): the air conditioner; a tiny bedside lamp with a tiny minuscule watt bulb; a shredder that can shred three pages at a time, also OFF; and the C-PAP machine. The only time two things are on at once is when I briefly have the night-light lamp turned on while I am putting on my C-PAP mask and then hitting ON.

I tried moving the plug for the air conditioner into the empty adapter socket, but it still rattled when I breathed out. WHY IS THIS HAPPENING? It has never made that noise when it is being an air conditioner in its ON position.

Obviously, I unplugged it, and now I could go to sleep except that I am both irritated and worried. Mostly irritated. 99 percent irritated, 1 percent worried.

The adapter has lights for Grounded and Protected and both are lit. Do you think everything is okay and I'm not going to have an electrical fire? That's my 1 percent question. My 99 percent question is WHY THE HELL does my air conditioner react to my breathing out???????

 

Thank you everyone! Such smart people here. All I have ever truly been able to understand about electricity is that it is fearsome and should be treated with awe and grave respect.

I knew things drew amperage even in the off position, but I didn't know it would be significant.

Thank you, EVERYBODY!!!! Now I can stop being mad at the air conditioner. LOL

 

@Morgotha, I had to unblock you to see why PepperAnn was so amused. Me, too. That was hilarious!

 

YES, you read that right. It took me forever to figure out that that was what was happening, because how could that even be one of the possibilities?? I was wandering around my bedroom with my cpap mask on listening at walls, because logically it could have been something scary with the wiring, right? But, no, it turned out to be the tower fan--in its off position.

After I read everything here, I actually did try tightening up the screws, but it's something on the inside that's clunking when I breathe out. So I left it unplugged. Next summer I will have to run an extension cord to get electricity to it.

The wall socket is behind the head of my bed, which is a bulky thing because it used to be a water bed. Now it has a heavy mattress on it. Lots of cooking magazines stored under the bed, pushed up against the waterbed platform. It was a real project to pull everything out and then brace myself and hurtle my entire weight against the bed to yank it away from the walls enough inches to be able to squeeze my hand in to where the socket is, and then start experimenting.

I was SO pissed.

 

It is a fan. I said AC because it is all I have to cool me down, but that's wrong--it's not an AC. I looked on the unit to see how it describes itself. It just has a brand name. It's an old fan, so no computer component that could be conversing with the C-PAP.

I have no explanation for how it makes noise in the off position when I am breathing out wearing my C-PAP mask. The decade it has stood there in the off position, it has been completely silent, just what we would expect.

Two ways to make it be silent.
One, unplug it.
Two, keep it plugged in, but don't use my C-PAP mask. If the C-PAP is on, but I'm not wearing the mask, the fan is silent. I had to be breathing via the mask to track down the source of the rattle. Seriously, I felt like Walter White in the episode about the fly, because this was just insane.

I tested it over and over, always with the fan in the off position, thinking maybe the C-PAP was making some part of the fan's innards vibrate. It didn't help when I tightened the fan's screws. It didn't help when I threw a blanket over the fan. It didn't help when I tried a different plug space on the adapter. I wish I had tried Sharpie's idea of unplugging the shredder just to see if that would matter to the fan, but I have already shoved the bed back into place, and I don't want to give myself another temper tantrum in the struggle that would be involved to pull it out from the wall again.

Also, I did try turning the fan on and then off at one point. To remind it of what OFF means. It didn't help. I also tried thumping the fan against the floor, because WTH and it deserved it. No difference.