Thanks guys. So I'm trying to put together a list of ideas for keeping the noise level down (not for my own ears in particular, but in general). Thinking of making two wooden boxes to collect the coins that come through, and I'd try to line those with some sort of carpet or rug. Not a whole lot more that can be done there, since coins will be striking coins. At the other end, a book covering the hopper in between refills would work.
Is it possible to slow down the feed speed, thereby reducing the sound produced by the motor? Or would a lower voltage cause a problem? I see there is a separate speed control, but I'm not looking to go for that at this time.