Monitor makes noise?

My wide screen HD Dell monitor lets out a subtle high pitch noise when I have it on. When I turn it off it stops. Does anyone know why this is and how I can stop it?
Thanks

A lot of electronic devices actually do; it is likely to be a power supply/transformer whistle/hum but it shouldn’t really be a distractable sound or really that audible unless you are in a silent room and close to it.

In fact my problem is not so strange: all screens produce noise, electromagnetically speaking, and you can listen to it with a simple radioIt’s because of induced currents and magnetic fields.

That carries an extra problem. We have:

* All monitors emanate electromagnetic radiation which depends on the shown image, and they can be captured with a radio.
* Some speakers are capable of syntonizing radio
* My LCD monitor has integrated speakers and always working, just touching the screen.
* Conclusion: each image I see, I also hear it, and I don't need extra devices to do that.

I have a solution: bring the volume to zero, or connect a headphone so that the sound stops going out the speakers. But anyway, if I you want to listen to music, it’s better to display a black background at the screen to reduce the radiations and thus interferences.