For something that has absolutely nothing to do with the sound of your system, RF interference/leakage testing is sure a pain in the butt; mainly since I'm handicapped and walk with a cane.
RF itself is way above our hearing range but different frequencies can mix on any non-linear element in the system, producing new frequencies that might be audible. Al mentioned it many times. Keep your system clean from interference (shielding, keeping things apart, using different outlets etc.). Anything can be the gateway, including speaker cables.