I'm always asking questions but this morning I found something that answers one of my own questions and thought it might be helpful to others:

1.4 Sones = 45 dB (a very quiet dishwasher)

3.5 Sones = 58 dB (moderate DW)

7.0 Sones = 68 dB (a 1200 CFM Modernaire running at max speed)

8 Sones = 70 dB

I've seen some fans advertised at 10 Sones and didn't know what that meant -- now I know -- that's loud.