Programs like Sound Lock limit the max volume of louder sounds while keeping quiet sounds at the exact same volume. It's meant for FPS games to boost the sounds of footsteps.

Are these allowed? I really like the benefit of finding keycards easily but don't want my ears destroyed by anglers :P (fyi i havent used these in any runs yet)

You'll get your answer in bout 3-5 business weeks

years*

I think it's fine