I have an app for my phone that measures sound in decibels (dB). I measured before and after with the phone in the same location for both measurements. Those two changes dropped it by an average of about 5 dB. Not massive, but it was enough. My wife was happier afterwards.
lilypa, thanks for the tips. I'll definitely give the belt and lube a try. And what a bonus that you actually measured the dB!
chrisg, mine is already in my home office/workshop, but my 11 month old is the next room over. Anything that I can do to deafen the noise is a plus. As for maintenance, do you have anything you'd recommend? I've been looking for an excuse to crack open the base and peak around inside.