The sound is also played for your co-players in multi-player, and you can hear it even when it doesn't apply to you. I find that OK; it's just a small beep, just right for the functionality; not forceful enough for Your turn, I'm afraid.
Sigh. I wish there was a variation of this game called Slow Golf. I played a round with someone earlier today, and both of us had to tackle work-related phone calls while advancing through the front 9 of Bethpage Black. We concluded: if there was a rule that required you to wait until that sound at 60 seconds before you were allowed to hit any shot, that would definitely increase our work productivity!