The noise the player makes when hitting another mob is very loud and obnoxious. I'm talking about the "thunk" and "swoop" sounds.

I decided to go into "Music & Sounds" to lower it. I'd rather not turn down all player sounds due to how important they are, but I assumed that I had no choice.

It turns out that none of the volume sliders except "Master Volume" affect the hit sound in any way! I tried putting all the other sliders to 0.