I don't think a horse can help it if he's distracted.
It's like this: you're in a quiet hall, you can hear a pin drop, all those tiny aids etc. You go out into traffic, and all you can hear is trucks and horns blasting. It's not your fault if you can't hear your soft-voiced companion.
Smacking him with the whip doesn't tell him: "If you don't hear me you're going to get it!" What it does is simply make a noise LOUDER than the distractions.
What you need is raise your voice, so to speak. Be LOUDER than the distractions, whatever it takes. Backing, and turning in circles, are time-honored techniques.
Lots of times just getting used to the commotion, in other words, experience, is all you need. Keep at it!