What causes my right AirPod to be quieter than the left?

I’ve had my (Gen 1) AirPods for just under two years, but my right AirPod has already started getting much quieter than the left. I’ve tried charging, resetting, and cleaning the AirPod, but nothing works. I have the volume balance at .50 just for it to sound even on both sides. If necessary information, I’m also currently going to trade school to get my welding certification, and deal with metal filings that sometimes get into the case, but I always clean the case as best I can every other day.

[Re-Titled by Moderator]

Original Title: Right AirPod Quiet