If your missus groans too loudly if your trying to be silent BR, you could always gag her. That usually does the trick.
Out of interest why are you trying to be silent? The little un ? If you can't be heard 3 doors away, probably not much point.
Partly the little'un, although she'd sleep through a stampede of manatee's, or at least it was the little'un in mind that got me wondering.
Now it has just become an experiment, quite an enjoyable at that.