Sometimes the motor will sound very loud depending up on the type of flooring it is sitting on. For example one on mine is on ceramic tile and that makes more noise that lino. To solve the problem just put a mat underneath it. I usually use one of those one with a water proof back (in case they decide to play with it ). That will usually take care of the noise issue.

I don't find the cleaning that back, but I just take it apart and stick it in the dishwasher (that way it is also sterilized). I do take the motor apart about once a month or so and clean out the "gunk" that build up.