Ummm....errrrr......done the experiment, purely in the interests of science mind you .

Our remote control egg is now bf's favorite toy ever. It isn't silent, but it's probably the quietest vibrator I've got. When in use...I can't tell if it can be detected...._I_ can hear the thing fine , but he says that he can't from several feet away. I should add, though, that we've not used it in public and I'm so very vocal that I'm not sure he'd hear the smoke alarm over me. At worst, it might sound like someone's ignoring a vibrating phone. Odds are, if there's any noise and some distance between people, no-one will hear a thing.

Maybe when bf gets back from his latest trip I could get him to help me field test it for you .