I like to be really loud when I masturbate, both moaning/groaning and talking dirty. Unfortunately, I live in an apartment building with fairly thin walls, so I can't really get too loud when I'm playing with myself at home.
The solution? I put on a skirt with no panties, get in the car, and hit the interstate after dusk. Driving along at 70 mph with the windows up (and too dark for anyone to see what I'm doing), I can be as loud as I want while I play with myself. I especially like shouting descriptions of what I'm doing or feeling, like : 'It feels so fucking good when I shove my finger in my pussy!' or 'I want to suck a cock so bad right now!' By the time I get home, my pussy is aching and dripping, and I can finish myself off safely and quietly on my own bed!