Noise is less of an issue than the cleanliness of your polishing. No kidding. When I began coughing up black phleghm, I knew it was time to spend the bucks for a FILTERED, power exhaust buffer. The good news is that when you buy a quality unit, the noise is modest and the air is SO much cleaner.
I have a Progress Tool Corp. buffer with built-in lights, powered exhaust through a filter, & double spindle Baldor motor. Does the work without bogging down and miracle of miracles, keeps the air clean. Of course that means you change the filter periodically and put it in your sweeps barrel…no sweat. It’s been a champ for about 3 decades now. The noise is minimal - certainly less than a vacuum sweeper. Just emits a hummmmm.
Here’s the other thing; you could bypass the buffer with a combination of 3M radial bristle discs and tumblers. Do consider buying Judy Hoch’s little book about mass finishing jewelry using tumblers. (Last I knew, Rio sells the book.) While you may not need the whole line-up of mechanical tumblers, it’s well worth reading about how to do it. She writes with common sense and personal experience. HOWEVER, I suspect that vibrating tumblers will create more noise than a quality buffer like I have. Rotary tumblers should be quieter. Just sayin’.
Judy in Kansas, where heat index is around 100F. Looking for a good rain tomorrow night - YAY!