Every day customers call up to order CD players, cassette machines, etc. and tell me that these will work okay into their XYZ 123 console because it accepts unbalanced inputs. Remember, the only reason balanced audio circuits were invented in the first place is noise rejection. Stop for a moment and think about it.
Computers are wonderful sources of all sorts of hash.
So, too, are fluorescent light fixtures. If so, then there s RF to worry about. All of these sources add to the noise being radiated in your facility. The concept of balanced audio was originated over a hundred years ago by the people who designed our telephone system in this country. The critical factor in this is known as common-mode rejection.