iPhone 12 static and hissing noises

I was on my iPhone 12 today and I noticed a weird static and hissing noise coming from both top and bottom speakers. I thought I hadn't turned my volume down but I had. I've had a look at some other posts about it and I'm not very impressed. I can put up with it but if it's going to become a bigger problem in the future then I really want to get it fixed.

So, it a very big issue/can it get worse over time? Are there anyways for me to fix this myself?