Fuzzy sound and crackeling in speaker

Well i just got this used 660lx, all seems to be great except the sound.... ( i refuse to send it back)...
I noticed when i try to use a program that requires sound you can hear this fuzzy high pitch sound with a few crackels here and there and its not suppose to be making sounds at that point, also when i use it in genral with typing or screen touch, i get that sound too if the screen clicks and key noises are activated, key is if i have on the sound i get those noises, if i dont have on the sound i dont get em at all....Could it be a grounding problem ? dust some where? or blown speaker..? any help or suggestons

It's EM leakage frm the CPU. My 720 is horrific with it. When you get a calendar reminded or turn the screen off (so a LED blinks) the tone goes with the LED.
The other 720 (Pinkie) is perfectly silent.

It is possible that there is a badly connected wire (unshielded part) in all likleyhood though it is down to the speaker not being shielded in general.