[friendster7]

Your cell phone emits a strong electromagnetic (radio) field. That can then interfere with the electronics in the monitor.

Typically a cell phone when it is not in use sends little 'chirps' out so it can talk to the cell towers around it, lets them know where it is in case somebody wants to call you, update the time, whatever else.

When you talk it links to the nearest free tower and radiates continuously. That is why you have so much more standby time compared to the talk time.

With the phone next to the computer the signal from the chirps are strong enough to induce significant voltages in the electronics of the monitor and the speakers, so you get a flicker and a click from the speakers.

It is probably a good idea to move your cell phone further away. The signal drops off quickly so you should not have to move it very far.