No hoping needed...that is the way it works...otherwise you could just get all kinds of wonky performance feedback from people shouting random commands and the watch acting on it.
If you want an example of a product that does JUST that...check out the Xbox One. It's probably one of the worst pieces of technology I've purchased in the last 5 years. You'll be playing a game, and someone you're playing with online can shout out a command such as "Xbox Menu" and in the middle of your game, the menu will pop up rendering you defenseless until you get it closed (which takes a few seconds). Also "Xbox Record That" is a fun one...it'll literally fill your video clip section with random and useless little 4-5 second video clips of...well...whatever is on the screen at the time.
It's mind bogglingly pitiful, especially for a "next gen" piece of video game technology.