Have hum on your audio? It’s a common problem, and can be maddening. A friend was having this problem, and asked me about it. Here was my reply:
Hum is usually a grounding problem.
Buy a five-dollar ground tester on Amazon or at walmart.
test your ground. If it’s bad, fix it. I paid an electrification 75 bucks to fix 6 in my home ten years ago.
If you rent, tell your landlord that it’s a safety hazard and ask if he’ll fix it.
There are different types of grounding problems. They range from annoying to possibly lethal.
If it’s not a grounding problem, maybe the current is just dirty in that house, or in that room. Run a grounded extension cord into another room.
and/or get a power conditioner.
Also, I’ve seen really strange problems that are solved by pointing the mic 90 degrees of where it is.
That’s usually a poorly insulated power line below the floor or in the wall acting as an electro magnet.
Try running your laptop on batteries for a minute and see if it fixes it. if so, it’s a ground loop.
Also, try moving cables away from the mic cable and away from the audio interface / laptop, see if it gets better or worse. That’s a good place to start.