What is it about electricity which makes my ear buzz?

June 15, 2009 5:32 AM

BurgeoningSuperPowerFilter: I can hear some electric fields. What causes this?

I first noticed this about 20 years ago, watching someone play with an electric train set. Everytime he turned it on, my right ear would buzz. There was a slight sensation with it, like some tiny insect was bumbling around in my ear. Now I notice the same thing for all sorts of appliances, including washing machines, my neighbour's car (alternator?) -- anything with a sizeable electric motor which might generate a magnetic field.

Is there a name for this? Is it related to (or likely to become) tinnitus? I'm not at all worried about it, not sure my doctor would be either, but I'd like some more info if possible.

posted by BrokenEnglish to health & fitness (21 comments total)

I've never heard of this happening (I'm a physicist and a doctor) although I can imagine electromagnetic induction of the acoustic nerve. Are you saying you feel a vibration? Any chance you have a piece of metal in your head?

If it's been going on for 20 years, you're right to not worry.

Aside: I've been wanting a fingertip magnet. Have even bought a magnet at Radio Shack, just haven't had the nerve to put it in yet.
posted by neuron at 5:44 AM on June 15

I don't think you're hearing the electric field directly; you're hearing ordinary noises of of frequencies that are right at the edges of the envelope of frequencies that people can hear; some people hear them, and some don't. I can hear some of those things; model train transformers, certainly, and TV sets. I used to be able to reliable tell that a TV was turned on in another room, even when the volume was turned down to nothing. Not so much with washing machines, though. Also, my hearing at those frequencies has faded as I've gotten older.
posted by jon1270 at 5:51 AM on June 15

Put me down as another one who often hears them too. Washing machines not so much, but other appliances, sure. Sometimes it's so loud I have to leave the room while other people can't hear a thing.
posted by Pollomacho at 5:56 AM on June 15

Are you 'hearing' the electric field or the 60 Hz fundamental of the power lines and maybe some overtones? I ask because I usually here the 60 Hz and that seems more likely than any other sense. Like from where I'm sitting I here the shush of the building mechanicals outside my office (which isn't 60 Hz), the buzz from the fluorescents (multiple of 60 Hz) and a high pitched squeal coming from my computer.

It's bad enough that in grade school my teachers insisted I had a hearing problem, after testing it turned out I don't, the worlds just too noisy.
posted by substrate at 6:02 AM on June 15

I vaguely remember hearing about something like this before. The two theories that were proposed to explain it were
a) electromagnetic induction of the acoustic nerve, so your acoustic nerve is somehow acting like a radio antenne
b) the possibility of having a bit of ferrous grit attached to or trapped behind your eardrum: a strong oscillating magnetic field would make an iron filing or steel flake trapped inside your ear vibrate very slightly. If this vibration got passed on through the ear's mechanisms, you'd interpret it as sound. I'm not enough of a physicist to guess how strong a magnetic field would need to be for this to work.

I'm sorry to say I never found out (or have forgotten) what the actual cause was in the case I heard about. Hopefully this will give you some clue for your future searches.
posted by metaBugs at 6:04 AM on June 15

I can hear high frequencies, my video instructor told me it's more common in women for some reason. Lights, electronic media. I find it a relief when they are off; I sleep better with my computer turned completely off instead of sleep mode.

I can hear the difference between the pitch on a CD, an audio tape, and an MP3 file.

The audio tapes cause tinnitus, so I limit how much I listen to them.
posted by effluvia at 6:28 AM on June 15

I get that too. Some electric motors, TVs, monitors, and some light fixtures will trigger it. I can tell if someone has switched something on in another room, sometimes, just from the high pitched frequency.
I'm going to Modern Jackass this one and say that the field creates an audible vibration that we're sensitive too.

(alternator?)
Ignition coils.
posted by Jon-o at 6:33 AM on June 15

To be more precise, it's like I can hear whatever it is moving around in my ear. Not the kind of hum or squeal you might usually associate with a transformer or fluorescent light. Kind of like the wobbling sensation that neuron's fingertip magnet might cause, or metaBugs's option (b). I've never been in a situation (eg, an accident, explosion) where actual fragments of actual metal might become embedded in there, but maybe a tiny piece could have drifted up there somehow.

Jon-o: Yes, ignition coils sounds right. He has a super-duper souped-up something-or-other, and I can tell immediately he's within 50 yards of my living room.
posted by BrokenEnglish at 6:44 AM on June 15

If this most often happens with things that have motors, you may be hearing the drive electronics. The H-bridge circuit that drives a cheapo DC motor, for example, may run at something like 15khz, which I can hear very clearly and which I find fantastically obnoxious, while other (usually older) people in my office don't seem to have an issue with it.

I have particularly sensitive hearing, since I was also able to hear a low-frequency sonar running underwater right next to a research boat, and it was right on the edge of my "hearing" -- I was barely aware of it and everyone else thought I was making it up. I also can't be in a room with a CRT television on mute (haven't tried it with an LCD yet). I've got some friends who are the same way, and other friends who think we're all crazy.
posted by olinerd at 6:52 AM on June 15

olinerd, I'm the same way with CRTs, and I can happily report that LCDs do not have this problem. I don't, however, think it's what BrokenEnglish is looking for, based on his description.
posted by Alterscape at 6:57 AM on June 15

Thanks to all for taking the time to respond.
posted by BrokenEnglish at 8:29 AM on June 15

Can you tell us about the pitch of the sound you're hearing? Is it low like transformer hum, and just located inside your ear instead of outside? Or is it higher pitched than that? Does it change in pitch or stay constant?
posted by nebulawindphone at 9:13 AM on June 15

Most everyone can hear the whine of a CRT, for example, when they are young, but we typically lose that range of hearing by the time we are adults. Electronic things create all sorts of spurious noises. It is no more mysterious or esoteric than any other whine or hum something electronic may produce, except for the fact that for most adults, our hearing is damaged enough to not even know it is there any more.

Very high pitched sounds tend to produce odd and inaccurate spatial localization - it is trivial to produce a high pitched tone that most listeners will perceive as "coming from the inside of my own head". High pitched sounds localize better, but something about how the brain processes location info gets a bit weird when the pitches get extremely high.

If your nerves were so sensitive as to be triggered by the electromagnetic impulses of electric motors, you would hallucinate and/or go into seizures whenever one was used in your vacinity - auditory nerves are not some special more more sensitive variety of nerve.
posted by idiopath at 9:22 AM on June 15

You haven't by any chance had malaria, have you?

The problem coming up with a mechanism to account for your perceptions is that nothing in a normal ear is ferromagnetic, which is why metaBugs very astutely raises "the possibility of having a bit of ferrous grit attached to or trapped behind your eardrum: a strong oscillating magnetic field would make an iron filing or steel flake trapped inside your ear vibrate very slightly. If this vibration got passed on through the ear's mechanisms, you'd interpret it as sound."

You have plenty of iron in your blood, but it's not one of the ferromagnetic forms. However, the malaria parasite metabolizes the iron-containing hemoglobin in your red blood cells and leaves behind (as a waste product as far as I know) tiny iron containing rods that are ferromagnetic to a degree:

It works like this. The parasite produces haemozoin in the form of rectangular rod-like crystals and, normally, the long axes point in random directions. "When you apply a [magnetic] field to them, they become magnetised and all orientate in the field direction," says Newman.

I seems entirely possible to me that parasitized blood cells could have broken apart under oxygen stress in your ears and deposited some of the rods in your eardrum-- enough to make them have the kind of response to electromagnetic fields you describe.

Interestingly, long term tinnitus in the aftermath of malaria is quite common, but it is generally attributed to quinine treatments. Of course, killing the parasites as quinine does could facilitate the deposition of these little rods in ears and elsewhere, but no doubt the tinnitus has been shown to be a direct effect of the drug.

I'd think the rods would need to be magnetized by an imposed external magnetic field to be responsive to fields, so perhaps your sensitivity, under this hypothesis, should be at a peak in the immediate wake of using headphones and earbuds.

I guess it could also be, under this very speculative hypothesis, that you could minimize the buzzing by applying one of those bulk tape degaussers to your ear.
posted by jamjam at 10:18 AM on June 15

Metafilter: Minimize the buzzing by applying one of those bulk tape degaussers to your ear.
posted by Slap*Happy at 10:42 AM on June 15

I can hear electric outlets (very faintly, if I put my ear near them), and the anti-teenager shriekers that they put up in malls. Never had any odd swamp diseases, but I do have exceedingly good hearing. It's my super power. :P
posted by Phalene at 12:10 PM on June 15

I always thought it was the capacitors buzzing. Don't really know why.
posted by I-baLL at 12:39 PM on June 15

Thinking about your question a little bit more, BrokenEnglish, it occurred to me that, though you are not complaining about anything, your account of what happens to you could be seen as a case of electromagnetic sensitivity.

I've been puzzled by the persistent reports, especially from the UK, of this phenomenon, and I'm not as inclined as the general consensus to dismiss them as hysteria.

The first person I've heard of who complained of electromagnetic sensitivity, and the only such person I know of to have enough of a searchable history to investigate, is Nikola Tesla (the only link I could find making this claim and which also quoted a primary source is here, on an electrosensitivity advocacy site, and I'm afraid the primary source is, at bottom, much more ambiguous than they seem to recognize). When I did a 'tesla malaria' search I found this on p.38 of Margaret Cheney's Tesla: Man Out of Time:

The boy continued his studies at a higher school in Karlstadt (Karlovac), Croatia, where the land was low and marshy and where, in consequence, he suffered repeated bouts with malaria.

It might be interesting to look at some of the people claiming to be Wi-Fi sensitive, for example, to see if they have a history of malaria.
posted by jamjam at 3:06 PM on June 15

To understand what's going on, we'd need to separate two separate possibilities: acoustic and electromagnetic.

If it's acoustic, your hearing is quite sensitive and you're hearing things that others can't. Test this hypothesis by putting in ear plugs. Can you still hear all the things you describe? If not, it's acoustic.

If you can still hear it, then there's a good possibility that it's electromagnetic — radio waves are affecting you.

Please let us know! This is quite interesting.
posted by exphysicist345 at 9:03 PM on June 15

More responses - most unexpected! I've never had malaria and never been to a tropical region, so I can rule that out although the side effects in relation to this seem fascinating in themselves.

I'm quite sure this is to do with the electromagnetic field which is produced. It's more like a sensation than a sound, and (thinking about it now) I can't remember if there is a distinct sound. But the sensation is strong enough to keep me awake at night. I thought for a while it might be some psychosomatic thing, but I'm fairly sure now that's not the case. Mercifully, it doesn't happen all the time or I'd never set foot in the server room again. It seems like some electro-mechanical devices just pack more of an electro-magnetic punch than others and that's when this weird thing happens.

If I wasn't slightly worried about tinnitus I probably would never have raised it but the responses have been very interesting even when they're probably not the answer to my question, so thanks again for taking an interest.
posted by BrokenEnglish at 4:37 AM on June 16

Can you still hear all the things you describe? If not, it's acoustic.

Unless the earplugs also work as insulators.
posted by Pollomacho at 5:34 AM on June 16