quote:
Originally posted by Stigmata
same happens with my pc...
it gets higher pitched when firefox is opened as well
A PC doesn't make high pitch noises (at least it shouldn't unless there is something terribly wrong
); it doesn't contain the electronics (like a moni) which can be responsible for such noises afaik. What can be causing the noise are rotating parts though. eg: bearings of fans, HDD motors..)
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EDIT: hmmm, now that I think about it (and remember my old PC's): unless you mean another kind of noise which is only heared when things on your screen change. This kind of high pitch noise is also heared when you move your mouse for example; thus when graphics on your screen change. But actually this is again either your monitor (though it isn't such a 'bad' sign as the high pitch noise described by DevilX) or it are the speakers which 'leak' this noise... as both recieve a radio wavelength distortion of some kind and this reflects to the inner electronics again.
Note: this is the same distortion you hear on loudspeakers when a near mobile phone searches for a network connection or recieves a message.
(mostlly noticeable on car radios)
=> this is also one of the reasons why you should
completely turn off your mobile phones in theaters, movie theaters, etc. Simply putting them on 'silence mode' is not enough; they still can disrupt the sound heared on the speakers and thus heared by the whole audiance in the room!!!!!.
/ 
