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Author Topic: Does electricity make noise?  (Read 14414 times)

Offline Dashrashi

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Does electricity make noise?
« on: 10/01/2006 04:26:36 »
I keep hearing this sort of high-pitched almost-metallic chittering sound coming from next to my bed, where many of the wires to appliances in my bedroom lie. I would almost swear that it's coming from the wires; my first instinct was that it was mice, but the sound doesn't go away even when I yell and push the bed into the wall/sound. Does this make sense? Is it possible for electrical wires to make a sort of chittering sound of their own accord? Or do I just have very fearless mice?


 

Offline neilep

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Re: Does electricity make noise?
« Reply #1 on: 10/01/2006 05:02:10 »
Welsome to the site Dasrashi.

How strange !

it is quite normal for there to be mains interference but I've never heard it described as you have described it so.

How many wires do you actually have there ?....if you have many and they are all bundles and intertwined together then you could be creating all manner of electro-magnetic interferences.

Have you literally got up, pulled the bed out and stuck your ear down there ?..if not...try it...

I hope someone here has an answer for you.

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another_someone

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Re: Does electricity make noise?
« Reply #2 on: 10/01/2006 05:35:34 »
Yes, my first instinct would also be magnetic effects, either between the wires themselves, or between the wires and some metallic object near by.

My next idea might sound crazy, but we do know that many living organisms are actually able to sense electric fields (some sharks are particularly good at this, being able to sense the electrical impulses the nerves send to muscles, and use this sense in hunting prey).  Is it possible that some people have a degree of sense of electric fields?
 

Offline DoctorBeaver

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Re: Does electricity make noise?
« Reply #3 on: 10/01/2006 14:44:44 »
quote:
My next idea might sound crazy, but we do know that many living organisms are actually able to sense electric fields (some sharks are particularly good at this, being able to sense the electrical impulses the nerves send to muscles, and use this sense in hunting prey). Is it possible that some people have a degree of sense of electric fields?


Sharks have special organs (the lateral line) which enables them to sense electrical fields. Humans don't have anything like that.
 

ROBERT

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Re: Does electricity make noise?
« Reply #4 on: 10/01/2006 15:00:42 »
Hi Dashrashi,
your electrical duct could be a rodent restaurant where the only things on the menu
are multi-coloured spaghetti and rat-at-chewy:-

""Rats eat their way through wood, and even soft metal.
They often chew through electrical wiring, creating a fire hazard.""
http://journeytoforever.org/at_rats.html
« Last Edit: 11/01/2006 12:01:40 by ROBERT »
 

Offline neilep

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Re: Does electricity make noise?
« Reply #5 on: 10/01/2006 16:15:46 »
So, as I see it...Dashrashi either has a shark living beneath his bed or it's a local hang out for a bunch of rats !

Well...I'm glad we solved that one !

Men are the same as women.... just inside out !!
 

Offline rosy

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Re: Does electricity make noise?
« Reply #6 on: 10/01/2006 22:00:23 »
I was driving home this evening, listening to some music, when I noticed a song lyric:
"Late at night when the wires in the walls/sing in tune with the din af the falls/I'm conducting it all while I sleep/..."
Which seems to be vaguely relevant... at least to the idea that it might be possible to hear something. No hints as to what, tho'

(The track is "Light up my room" by the Barenaked Ladies
 

Offline chris

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Re: Does electricity make noise?
« Reply #7 on: 10/01/2006 22:31:42 »
Electricity and magnetism are linked. Hence we use the term 'electromagnetic radiation' to describe a radio wave. In this instance a changing electrical field creates a changing magnetic field by distoring space-time, and the changing magnetic field then creates an electric field and so on. The effect propagates as a wave - in other words an electromagnetic wave.

But your ears are not tuned to this kind of wave. Instead our ears detect mechanical displacements - or vibrations - which the cochlea (inner ear) converts into electrical signals that the brain can understand. Therefore, to be hearing strange sounds coming from near your bed, there must be something vibrating close by.

Now the lowest frequency that we can hear is about 20 Hz, and the highest about 20,000 Hz. Mains electricity is an alternating current (meaning that it cycles between plus and minus) at 50Hz. So things powered by mains voltages sometimes 'buzz' - because they contain components - often transformers - which hum (vibrate) at twice this frequency (because the voltage returns to zero twice per cycle), producing a 100Hz noise, well within the realms of human hearing. This is certainly true of the older designs of strip lights which have a "ballast inductor" that helps them to start and limits the running current.

But higher pitches are also possible. More modern strip lights, for instance, use transistors to increase the frequency of the applied current with the aim of providing a smoother (more continuous) light - as opposed to one that effectively switches off 100 times a second. These can produce an even higher pitched whining.

If the noise is continuous and unvarying then it almost certainly is electrical. Have a look for transformers, junction boxes, and trip systems attached to the wall. The culprit system might also be attached to the other side of the wall, so you'll need to do some hunting...but not with a drill !

Chris


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another_someone

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Re: Does electricity make noise?
« Reply #8 on: 10/01/2006 23:33:20 »
quote:
Originally posted by chris

Electricity and magnetism are linked. Hence we use the term 'electromagnetic radiation' to describe a radio wave. In this instance a changing electrical field creates a changing magnetic field by distoring space-time, and the changing magnetic field then creates an electric field and so on. The effect propagates as a wave - in other words an electromagnetic wave.

But your ears are not tuned to this kind of wave. Instead our ears detect mechanical displacements - or vibrations - which the cochlea (inner ear) converts into electrical signals that the brain can understand. Therefore, to be hearing strange sounds coming from near your bed, there must be something vibrating close by.




If you listen live to a church organ, you will perceive frequencies well below the lower limits your ears can perceive, but those sounds are not being heard by your ears, but by the vibration going through your whole body.

I would doubt that any sense of electric field is through the ears, even if the brain may sense it as being such (but then, we know with synaesthesia, the brain can receive a sensation from one sense and interpret it in another sense).

We know that the body is sensitive to electrical currents in even small amounts (hence we perceive electric shocks).  There has been much debate, and no conclusive evidence one way or the other whether living beneath power lines causes a perceptible biological effect upon the human body.

Can we say with certainty that the human body cannot detect the presence of an alternating electric field in close proximity to a live mains cable?  For the most part, I would suspect that the human brain could not interpret the sensation, and so generally ignores it; but I could well imagine that some people's brains may interpret the sensation in terms of sound, even though it did not originate from the ears.

I am not saying that this is what is happening, only asking whether we have adequate evidence to say it cannot be happening?
 

Offline DoctorBeaver

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Re: Does electricity make noise?
« Reply #9 on: 11/01/2006 02:17:09 »
quote:
Originally posted by another_someone
Can we say with certainty that the human body cannot detect the presence of an alternating electric field in close proximity to a live mains cable?  For the most part, I would suspect that the human brain could not interpret the sensation, and so generally ignores it; but I could well imagine that some people's brains may interpret the sensation in terms of sound, even though it did not originate from the ears.



That's interesting. Maybe it IS a type of synaesthesia; or, at least, a related phenomenon. If the processing of 1 sensory input causes activity in a different sensory-processing part of the brain, I suppose it could be possible for other parts of the brain to be stimulated by an external electrical field and, in turn, cause activity in the audiosensory part.
 

Offline wbeaty

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Re: Does electricity make noise?
« Reply #10 on: 11/01/2006 05:05:19 »

UNPLUG THE WIRES!!!

If the sound stops, then it was electrical.


Also...  wires certainly do emit sound if the current is sharply pulsed.  The magnetic fields can wiggle the wires slightly, and if the fields are pulsed, this wiggle makes sounds of a frequency that humans can hear.  Light dimmers and variable heater controls create the right kind of pulsed current because they sharply switch the AC on and off.

People who work on theater lighting are familar with this same phenomenon.  The lighting dimmers cause the wires to "whine."  Especially the filaments inside the light bulbs will make buzzy-squealie noises whenever their brightness gets changed.
 

Offline wbeaty

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Re: Does electricity make noise?
« Reply #11 on: 11/01/2006 05:07:00 »

UNPLUG ALL THE WIRES!

If the noise stops, then it was electrical.
 

Offline wbeaty

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Re: Does electricity make noise?
« Reply #12 on: 11/01/2006 05:10:02 »

Also, wires can certainly make sounds if the current is sharply pulsed.  This effect is well known to people working in stage productions.  The lighting dimmers produced pulsed current especially when the lights are turned down low.  The sharp pulses create pulsed magnetic fields which wiggle the wires at a frequency which produces audible sounds.  This especially is noticable in the filaments of lightbulbs.  When the stagelight dimmer board is used to change the brightness, the light bulbs make buzzy-squealie sounds.

Might there be a light dimmer or a variable heater control plugged into the wall by your bed?  If so, that's the thing that's making the noisy wires.

 

ROBERT

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Re: Does electricity make noise?
« Reply #13 on: 11/01/2006 11:07:35 »
quote:
Originally posted by Dashrashi

 Is it possible for electrical wires to make a sort of chittering sound of their own accord? Or do I just have very fearless mice?



Electrical wires can make a sound, it is called arcing (sparking).

Alternatively you may have an infestation of insects rather than rodents.

Wbeaty has the right idea, if you temporarily switch off the main power supply to your home,
(if it is safe to do so), and the noise stops then is is electrical.

(Central heating pipes / air conditioning ducts can coincide with electrical ducting,
vibrations from the motor used to move water/air are readily transmitted along the pipes/ducts).
« Last Edit: 11/01/2006 12:19:21 by ROBERT »
 

Offline Sandwalker

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Re: Does electricity make noise?
« Reply #14 on: 13/01/2006 16:13:16 »
Many a transformer/adapter has a habit of humming, for example my bedroom CD clock radio unit (mains attached) has a low 50Hz/100Hz hum on standby.

Also how many appliances are you runnung and off how many outlets, check than none of he cables are warm to the touch, this may indicate that you are overloading the wireing.

Do not daisy chain multi-gang extentsion leads, most are rated at 13A (UK) or less, if you can, connect them to seperate outlet points.

Try disconnecting each device, when/if the noise stops then that was the device causing the problem. Have the device checked.

Some televisions give off a high pitched whine which can usually be heard by healthy young ears (I used to hear it!).

Otherwise its something else alive or not.



I could not join any group that would have me as a member!
« Last Edit: 13/01/2006 16:17:20 by Sandwalker »
 

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Re: Does electricity make noise?
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