need a small headset that is NOT push to talk

[californiacoyotes]

is there a small headset that can be used with the motorola talkabouts that is NOT push to talk? i need one that is voice activated. i need a voice activated set up because i will be using it on dirt bikes, actually my son will be on a dirt bike and myself on an ATV. i don't want my son to have to mess with a push button while we are riding.

cc

[deerguide]

Problem with a VOX activated mike is that it will trigger with most any sound including the engine noise. I tried to come up with something a while back when I was into ultra-lights, but couldn't get anything to work other than the push to talk.