There are different kinds of loud, too.
B-1Bs are ear rattling, as with most aircraft with afterburner. A Harrier in the hover is just a sustained loudness that you sort of get used to. You wouldn't be able to keep your hands away from your ears for too long if a Harrier in the hover sounded like a B-1B!
It was actually louder in the first shot, where it was coming in slowly, at about 40-50ft up, and 25ft away (at an estimate).
And although you may think the three Harriers coming in would be loud, have you ever stopped to think about how loud the Red Arrows would be if that kind of science applied? They're certainly not 9x louder than a single Hawk!

Thanks for the comments, anyway!