What am I blabbing about? So back in the day I put together a sound system for the theatre. I spent the right amount of money on a board, cables and speakers. Good system, should do most anything we need. At that time I was using Regina's lap top to run a cheap sound program Aaron Rose helped me find for 50 bucks. Then Domtar had some old computers on sale for $40 each, so I grabbed them and wha la, a permanent sound effect system.
But $40 gets you $40 worth of computer stuff. We'd been using the on board sound card and every now and again it has some issues. So I finally got an external sound interface to upgrade and remove the 60 Hz hum that has been plaguing us. Yeah no more hum, buuuut every once in a while we have these weird thumping noises and interference. I incorrectly (I think) blamed it on the computer again.
What it ended up being (I think) is that in a 2' radius around the sound board we are an electromagnetic field nightmare! Any cell phones, wi-fi, wireless mic, or other signal that intermittently transmits causes a pulsing in the sound. All of our cables are shielded, but there's such a massive amount of power coursing through a 2' area, that any signal gets picked up.
The only signal I'm leaving alone is the transmitter for the light grid, cause that's a whole 'nother can of worms. We'll see if I'm right, last night I kept the signals away and there was no interference. Time will tell.....
Here's a neat quick primer on EM problems in audio: https://itstillworks.com/eliminate-electromagnetic-interference-12281784.html
Maybe someday we'll go to the future and do optical sound transmission. Probably should make sure the rent is paid first.....
Stay Techie my friends!