A:Answer I guess this is pretty subjective, I am have not measured the decibel levels.
When the unit is cleaning the vacuum (noise) is much less than a regular full size vacuum cleaner. I have the unit running in front of my office (home) while on conference calls and can hear just fine. Now, when the robot docks and the bin is "evacuated" into the docking station bag, it sounds like a jet engine. Since this only lasts 10 seconds or so, it is tolerable.
I've been using it for a couple of weeks now, and it keeps the dog hair (Lab) under control. It does take a while to clean though. For approximately 2000 sq ft (mix of carpet, tile and hardwood, it take around 7hrs (multiple charges needed to complete the entire job).