Is it really just me?

Flickering lights affect me negatively. I have to leave the room asap or suffer sore eyes or possibly even a migraine headache, yet others in the room are able to cope with it (some don’t even notice any flicker). Fluorescent lighting is usually the culprit (ballast or tube in need of replacement) and sometimes an audible humming also is present. At very close distances from the bulb (under 10-feet) a peculiar feeling of physical assault is sometimes experienced. It’s something I cannot ignore and the only relief is to turn off the offending lamp or to leave the area. Perhaps you are sensitive in a way not altogether different than me. Good luck dealing with this.

What is typically the sum in these three registers, and where exactly are you located?

 

anything thats electro magnetic i hear a hisss sound, so its everywhere, it really bothers me during homework and stuff, but i dont get headachs or anything

 

This is interesting. I was playing with an electronics kit thing the other night. One of the circuits was a simple one transistor amplifier hooked up to an ear phone. The instructions were to touch the lead that lead to the base of the transistor and in the earphone you would hear the faint buzzing of all the stray EM signals that were in the area and that your body was picking up like an antenna. I was sitting right next to a fluorescent lamp so the buzzing was not faint at all. When I touched the lamp it rose dramatically in volume. When I shut the lamp off it diminished considerably.

This proves that people are, indeed, picking up EM signals with their body.

How this is being amplified and channeled into your ears, though, is a total mystery to me.

The pressure on your head and forehead might be either migraine or simple partial seizure symptoms. Most people aren't aware that Migraine doesn't necessarily have to include the tremendous headache.

Alot of people with seizures swear that they are affected by close proximity to anything with an EM field around it: motors, microwaves, fluorescent lamps, etc. I haven't happened to find any studies that back this up, but there is nothing really unscientific about the claim, since it has been proven that they have "touchier" neurons.

 

Guys, I've never really told anyone else about this, but here it goes. (deep breath) When I was a little lad, (about 3 years ago ) I was abducted by aliens. They took me into one of their ships to do... experiments on me. Now I have trouble sleeping at night, the last thing they said to me was "you are the walrus." And I make weird noises when I sneeze.

 

now i'm scared

 

now i'm really scared
actualy i dont disbelieve your story, if it happened, man that should be out of this world, i cant imagine it, frankly i dont want to imagine it, i would hate being an experiment, think about it though, our world includes earth, and we do experiments on more primitive creatures, say their world is the solar system, and they do experiements on more primitive creatures(us) and on and on, it makes sense, its crazy, i would rather communicate with them instead of being an experiment though.

my cousin went through a simular experience

 

Ah-choo! I am the Walrus!

 

He's just being a smart aleck. Pay no attention to him.

 

Paul Mcartney is the walrus, dont you know that

 

I get something vaguely like that. If the TV monitor is on but not picking up any TV programs, if I walk into the room I can nonetheless sense (somehow) that it's on. I don't really notice any noise, but when I turn it off the room seems to get quieter. I only get that experience with this one particular TV though. I'm pretty sure it's not just a faint noise the TV makes, or at least that's not how I experience it-- I just get a nebulous impression that something is there, and when I shut the TV off it leaves.

 

TV's emit a fairly loud, very high-pitched whine. It is beyond the range of many people's hearing, so they don't believe it happens. I hear it, and it really annoys me. Some sets are worse than others. When I go shopping for a TV, the most important thing I check is how loud the whine is.

Njorl

 

i pick up that whine also, bugs the **** out of me, but my whole family doesnt pick it up, they think the tv is off, then i go and close their like WTF i thought it was off, sheesh

 

I can also hear the TV whine; at least in some sets. I could tell from another room if the old TV's were on or not. Since the advent of the instant-on technology I can hear the TV constantly. I have learned to ignore it, but I can also tune in at will. I can also hear flourescent lights.

I think this is actually a ~20Khz noise produced in the flyback [high voltage] circuit. Same for the flourescent lights. Some lighting systems use 20KHZ precisely; right at the upper limit of our hearing.

 

Silly me. I forgot to mention that switching power supplies, such as those used in computers and cash registers, can emit noise in the 20KHz range. For some time this became a fairly standard switching frequency.

I think what happens is that inductors in the circuit, such as those that use a ferrite toroid as a core, can produce audible noise as a result of the mechanical stress of the varying magnetic field around them. Also, after thinking about it I could swear that while doing circuit design I have been able to hear transistors and op amps switching at certain frequencies.

 

60Hz low voltage [110 volts] AC, and high frequency switching that's used to produce the high voltage for the light itself. Its all or mostly in the transformers, I think.

 

Expanding on what Ivan proposed:

There is a very small gap built in to the ferrite core of the TV flyback transformer across which the magnetic field "flys back" when the coil is deexited after every pulse of current into it.

I think it is somewhere here you will find the source of the whine, probably the core vibrating by magnetostriction, like an elecromagnetically operated tuning fork, since the gap gives them the freedom to oscillate.

 

Good point! I had forgotten about that. It really is a ready made tuning fork.

 

I just did a little reading about magnetosriction and discovered that this doesn't have to be the case. Apparently they can devise ferroceramic cores that won't succumb to magnetostriction:

"...soft ferrites having a high initial susceptibility are those in which the magnetostriction is small, and it just happens that whereas the magnetostriction of ferrous ferrite FeO.Fe₂O₃ (magnetite) is positive, that of all others is negative. Consequently by mixing any ferrite with magnetite in suitable proportions a mixed system may be made whose magnetostriction is zero and which therefore has a high initial susceptibility."

-Magnetism, An Introductory survey
E.W.Lee
Dover Books 1963

I have a couple/three TV flybacks laying around and the cores are clearly ferroceramic. So, it is possible they are the zero magnetostriction kind.
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Cameras that have capacitor activated flashes seem to kind of hum/whine while the caps are charging. Do they put something in the circuit to deliberately make that noise so you'll know it is charging or is that the natural sound of the circuit?

 

I'm not sure if magnetostriction is needed in order to produce some noice. This term involves a change in length in the semi-toroid - uniformly and at the atomic scale. I think mechanical stresses acting across the gap might still make the toroid "ring". In other words, I'm thinking that the forces that act to compress the toroid in the case of magnetostriction could still act to strain the material in a macroscopic, mechanical sense. Assuming that I haven't mixed up my stress, strain, torque, and compress terminologies here. :yuck: