If you ARE NOT doing a visible count. Nor keeping a non-visible count. Then are you really counting the number of dribbles a player is taking?

If there is 5 seconds on the clock when a team makes a throw-in, then I will be performing a silent count. Once I get to 5 (in my head) I will try to take a peak at the clock to see why the horn has not sounded. If it still reads 5 seconds I will sound the whistle and say game is over.