No, no, no...
It goes like this...
You're in a small restaurant and you know the waiter
1 Way, just finished your starter, so you shout through to the kitchen for the main course. You don't hear back, but luckily enough (on this occiasion) he heard you anyway and brings it though - but next week, you might not be so lucky.
2 Way, just finished your starter, so you shout through to the kitchen for the main course. He shouts back 'OK you fat *******' and brings it though. You would know if he didn't hear you.