Sonicare Elite E9500
Having used the Oral B Professional toothbrush, I find the Sonicare e9500 to be quieter, a lttle measier to manipulate, and equivalent in cleaning efficiency. The Sonicare battery takes several hours to recharge, but then lasts two weeks. The audible timer is more beneficial than I would have thought. I just purchased another for my girlfriend. Highly recommended.
This is a really good power toothbrush (the e9500). My dentist sold me one, then I bought one for my mother. I like the 30-sec increment timer so I can consistently brush each surface of my teeth. Refills are very expensive (kinda like inkjet refills), so you may wanna disregard the recommended changing interval.