Have you asked other people if they can hear this sound? (If this question has been asked, I missed it in two readings of the thread.)
I am rather hearing impaired but have had to try to locate and fix sounds like this a few times.
I use this program, running on a laptop and a basic microphone. It looks a bit daunting at first but is pretty easy to use.
Offending sounds can appear as lines on the spectrum display. Move the mic around, touching various surfaces and look for changes in the lines. Ignore the ones that appear even when the mic is unplugged.
Yes, I am a geek.
If you don’t mind my asking, how old are you? I ask because normally adults can’t hear all the way up to 20k.
Also, it’s a shot in the dark, but could any business in your neighborhood be using the mosquito teen deterrent?
Long shot at that frequency, but I would just remind you that the telephone is independently powered by the telco.
I’ll second the very high pitched sound coming from a barely leaking toilet bowl as a possibilty.
While I doubt this is it, here is another possibility. My father once kept hearing stuff in his bedroom. He would lay down to sleep, and after a long while while trying to get to sleep, or waking up in the middle of the night, he would hear this extremely faint sound. The kind so faint you only hear in the dead of the night, and you can’t even be sure its not just that “sound” you hear when there is no sound to hear.
He would get up, turn on the lights, and try to trace it down, with no success. It usually stopped immediately when he got up. It drove him batty for a few weeks.
The culprit ?
A colony of carpenter? ants had moved into the bedroom wall clossest to the head of the bed. Only when things were really quite would they be active. The slightest movement or light caused by my dad and they would quite down.
I don’t want to imply that you are imagining things, but, do other people notice the same sound when they go into the room.
16-18kHz is freaking high. So high that most people can’t hear it.
High frequencies are very directional. They also bounce off of walls without losing much volume. This is why it’s sounding like it’s coming from everywhere. You could hang blankets and such around the walls, which would absorb the sound rather than reflecting it and might help ascertain a source. Possibly not, though, if it’s a non-point source like a water pipe.
Have you gone into the attic?
‘Slightly hearing impaired’? Could it be a
‘Slightly hearing impaired’? Could it be a quite different sound setting off a tinnitus reaction? Did you ever try a hearing aid and then dump it somewhere? I knew somebody who would always let his get out of adjustment that gave off such a whine so directional that tyhe slightest off-beam couldn’t hear it but when on-beam it was impossible to know exactly where it was coming from. Something like that could be bouncing around a normal sized room. Then again it could be something rotary beaming into the room with a worn bearing.
I’ve dealt with what seem like similar sounds myself. In my case, it was the springs in the window casings. I guess some combination of wind, temperature, humidity - whatever - can set the spring to vibrating. I’ve been amazed at how consistent and long term it can be. I only thought of this because you said your windows are covered - so it might be hard to identify them as the source.
Do you have compact fluorescent lights in the other rooms of your house? Those things drive me nuts with their high pitched whine.
I know you have tried turning off the power to your room but the whine still could be coming from another area of the house.
Another source if you have natural gas to your house is the gas meters can develop a whine. If you just started using your heat again after the summer that might be something to check.
One other possibility: have you gone to lengths (maybe due to the sleep disorder) to make your bedroom quieter than the rest of the house, such that, if you were experiencing mild tinnitus, it would be masked by ambient sound everywhere but your bedroom?
I know you said you checked everywhere in the room, but have you actually moved the bed to check thoroughly under there? Battery operated toys tend to find themselves in some pretty obscure places. Are you sure you don’t have any, you know, adult toys down there? I’ve found some stuff under the bed in the past that I had completely forgotten about, and also a couple things that guests stashed and I didn’t know were even under there! (and they apparently forgot)
I’m no structural engineer or any other kind of expert, but I keep thinking it’s connected with your windows. You didn’t describe what you did, but I suspect you’ve got an air flow trap somewhere which is causing a vibration. Maybe NinetyWt or one of the other engineering types around here could comment on this.
Everytime I find one of those wayard battery powered ear massagers I put it on Craigs list…
Ain’t that the truth! 
The dog, and tuning per se won’t fix it.
Whether or not the piano is in tune is irrelevant. Your piano has one “leaking damper” which is allowing its associated string to resonate sympathetically with the dog’s howling.
Call a Piano Technician. If the piano hasn’t been tuned for more than a year or two, it’s overdue anyway, and during the same appointment your PT can address the damper problem; Depending on the age, condition, and type of piano, it can be an extremely simple adjustment, or a more complicated adjustment or repair.
(I’ve been retired for a few years now, but I was a full-time professional Piano Technician for 32 years.)
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Does that work with saxophones? 'Cause I’ve got one that plays an Eric Dolphy solo every time there’s a full moon. (The realtor swore those Indian-burial-ground rumors were just talk, too.)
Sorry for all the wise-ass comments; I’m mostly stopping by to bump this thread so ambushed will come back and TELL US WHAT IT WAS! I’m dying to find out. (Yes, I have no life.)
Thanks for all the assistance and suggestions, everyone!
I have to spend a lot of time at the hospital with my Mom, which is one of the several reasons it’s so difficult to get back here very often. But when I entered the room early Thursday, the sound was gone!
I was never able narrow down the source of the noise. I followed all the advice and suggestions you folks so kindly offered, including rummaging through every single drawer, closest, enclosure, speaker, box, under and around the bed, etc., etc., and could find nothing. I had planned to cut all the circuit breakers that same day, but it was already gone.
I understand that it might have disappeared as a result of some battery-operated device whose battery died in the meantime, but I never found anything else that was battery operated except the backup battery in my alarm clock, the smoke detector, and the CO detector, and I’d already removed the battery from them all several days ago.
If it returns, I’ll try turning off all the breakers, but note that I had not heard the sound in all the previous time I lived here.
I’ll answer a few more posts, but I have to get back to the hospital.
Thanks again.
Sorry, I should have mentioned that. Yes, others could hear it (but, as my previous post reports, it’s now gone).
It was about 63-67 dB.
Oh, yes, I’m very familiar with tinnitus and other physiological sources of strange sounds in the ears. Several years ago, I experienced a low-frequency rumble in one year for over a year that pretty much only occurred when I listed to music. Audiologists spent quite some time trying to find it, but their techniques weren’t up to the job. They sent me to an aural surgeon who thought he’d identified the cause (something to do with a particular muscle or something that he insisted was too loose or something like that; I don’t recall the details anymore). He wanted to operate, but I found the risk of permanent hearing loss as a possible result of the surgery to be far more frightening than living with the rumble, so I passed.
Good thing I did, because after a few more months, the rumble disappeared, and it has never returned. Perhaps my body healed the muscle or tendon or whatever it was on its own.