That reminds me
When I was too young of a kid for my mother to leave me at home when she went shopping, I got dragged along, much to my discontent. The worst place was a big Sears store. I told ma that there was a high-pitched whine that I could hear as soon as we walked in the door, and it never let up until we left the store. She thought I was making it up so as to get her to hurry up with her shopping and leave. I wasn't making it up. I don't know what caused it, but I presume only young ears such as mine could detect it. I don't know how burglar alarms work, but surely the store couldn't leave an alarm on when the store is open for business, so I think that explanation is out.
I think that you were probably hearing the ballast's for the flourescent lights. Some of the high efficiency variety operate at 20 KHz - just at the upper end of the range of human hearing. I guess it could have also could have been something in the PA system.
Now that PWM circuits are into the >40 KHz range [really anything much >20KHz is all that we need] the noise should go away. Maybe your hearing is just as good as before; the lights have just grown quiet.
So the ballast might have something in it (transformer?) that responds to the 20 kHz current in the circuit in such a way that it mechanically vibrates at that frequency, and I was hearing sound waves coming off of that object?
I often work with variable frequency motor control equipment. If I set the carrier wave to 20 Khz it about drives me up the wall. In my case, the noise can be heard coming from both the drive and the motor.
Some in Kokomo report high-pitched (may be due to public PA system or city Fluorescent lights) but many report it as low-pitched. I would find out the radius of the low-pitched drone and try to find it's source. The low frequency is probably at the low end of the hearing spectrum.
janitor, I had the same thing happen to me when I was little. I have asked nearly everyone I have ever spoken with if it had happened to them and the answer was always NO. I thought I was crazy. Thank you.
Back then I was certain it was all of the metal coat hangers being moved by the shoppers on the metal pipes.
Now I'm thinking it was piped in 'white noise' to keep sound contained to each area of the stores.
Some older security systems used ultrasonic motion detectors to monitor spaces that should be off-limits to unauthorized people. Perhaps an alcove at the entrance of a bank vault or a storage room where valuable merchandise is kept. The bank in my old home town had evidently installed one in the early 1970's because when I went there to deposit pay from my summer jobs, the high-pitched whine drove me nuts. There was a convenience store in Gardiner that had one, too. They did a thriving business in cigarettes, and I assume the owner was restricting access to his stock-room. At my age (55) I can hear that nasty mosquito ring-tone some kids are using, and when we moved into this house, there was a persistent whine that was driving me nuts. The previous owner had plugged in ultrasonic pest repellent devices in the attached garage and the basement.
So, this thread doesn't become "ho-hum" there's also the Taos hum. And hums a lots of places.
About 99% of people in Taos NM cannot hear anything. I know this first hand. I'm certain some people truly hear something. Then there are lots of kooks. I think they prevent any researcher from getting useful data about sources.
I could hear ultrasonic motion detectors and dog whistles until I was about 45.
Worst incident for me was at one of my son's parent teacher nights. I walked in one door and when I left thru the othe door I screamed. The emitter was in the door alcove about a foot over my head.
I got a lot of weird looks out of that one.
No one else could hear it.
There were a number of stores I refused to go into. :grumpy:
I know one other person who could also hear this stuff.
Someone reported their hum lessened after limiting calcium by way of dairy products. The hypothesis they were considering concerned calcite crystals.
It seems possible (all things considered) that some dairy products might also contain higher than acceptable levels of various metals.
It might sound a little "out there", but does anyone have any thoughts about that possibility in relation to an enhanced or altered senses?
I have some circumstantial evidence that this might be the case. There is a genetic condition called William's Syndrome which, among many other things, includes:
I saw a special about William's Syndrome on television a few years back. The little girl who was primarily featured had downright superhuman hearing. She heard Dr. Sacks, the host, talking softly about her to the camera in a department store when he was standing in the next aisle over. Very soft sounds that most cannot hear can be clear as a bell to them.
I have no idea why elevated calcium levels might contribute to this, but they have that also, so there may well be a connection.
The possibility of William's Syndrome type chemistry seems even more reasonable if reports the 'hum' often has a seasonal component are valid. It would be interesting to know what common denominators hearers share in relation to diet and exposure to sunlight as well.
Why? I don't follow.
My guess is that there is some type of non-William's related high calcium syndrome ongoing in the general population everywhere and that there actually is some hum at these locations which people with this syndrome can hear but to which others are insensible.
Hey, whore you calling "insensible"?
Zoobyshoe- I meant unusual chemistry in a broader sense. Perhaps ionized calcium levels rather than circulating, or something along those lines. Many hearers have had fairly extensive physical exams. You'd think, given basic testing, someone would have caught a connection if blood calcium levels were higher or lower than normal. If I understand correctly blood calcium can register as normal, yet ionized can be sub-normal under certain conditions?
I'm not sure of the mechanism but I think vitamin D levels also affect how the body absorbs minerals. Hence the thought about seasonal variations in sunlight. With recent news about the skeleton being an active part of the endocrine system perhaps this is another area to research.
There also seems to be a predominance of people that start sensing the hum that are in their 40's. Perhaps this also points to some sort of age related metabolic change that isn't understood in the usual sense.
I also agree there may be a universal hum that some people can hear and others cannot.
It's difficult to understand how some hearers have heard it for the first time in the middle of nowhere away from any sort of mechanical sound or electrical source. The reports that the intensity often shifts around 3AM is another point to ponder.
If, as you say, people have thought to limit intake of calcium, I would suspect high levels were found in physical exams.
No, what I suggested was that people with these calcium problems may be evenly spread throughout the general population but that the hums are localized.
If we had a big budget we could round up a bunch of people with William's Syndrome and take them to Taos to see if they hear the hum.
From what I gather this is purely on their own after reading about calcite crystals. Note: lLmiting calcium intake should be discussed with a medical professional.
<<No, what I suggested was that people with these calcium problems may be evenly spread throughout the general population but that the hums are localized.>>
Or maybe the hum is evenly spread and calcium problems are localized.
<<If we had a big budget we could round up a bunch of people with William's Syndrome and take them to Taos to see if they hear the hum.>>
Recent research from NZ produced a recording that many hearers in other countries recognize as their hum, or very similar to it. The NZ researchers have yet to find the source.
Found this article on the Taos hum. Some interesting ideas.
Please use only reputable sources when quoting scientific theories or explanations. Crystalinks is not a reputable source.
If the quoted works are trustworthy then there should be a better source. If not found elsewhere then it can't be trusted anyway.
Separate names with a comma.