MC3PHAC Ground loopsGround loops are a major cause of noise, hum, and interference in audio, video, and computer systems. They do not in themselves create an electric shock hazard, the inappropriate connections that cause a ground often result in poor electrical bonding, which is explicitly required by safety regulations in certain circumstances. In any case the voltage difference between the ground terminals of each item of equipment is small. A severe risk of electric shock occurs when equipment grounds are improperly removed in an attempt to cure the problems thought to be caused by ground loops.