But that still doesn't allow him to speak, since you can't speak with your mouth closed (normally anyway).

What we've figured out is:
-you don't have to touch it (Ibara triggered it as he dived off the ship)
-you can't trigger it by yelling through a loudspeaker (though certainly Ibara thought you could - hence he freaked out)
-you can't trigger it just with intent (or else Ibara need not put it in his mouth)