While watching the Panthers/Buccaneers Monday night game, the Suze asked: Why do the referees use hand signals to indicate penalties? Don't they have microphones?

The answer is not, as I originally stated, that the NFL has a larger-than-usual following among deaf people.  Instead, the answer is a combination of utility and tradition.

Here's the utility:  When football was started and microphones were not available, the hand signals were necessary as a way for the referees to signal to the press box and the coaches on the sideline what penalty had been called.  The hand signals are still used in that capacity today - you may notice, the Suze, that the referee will signal the penalty to the sideline before announcing it over the PA system.  This gives the coach the opportunity to indicate whether or not they want to accept the penalty (on procedural penalties where the coach will not ever decline, such as a false start, this step is skipped).  The hand signals are also used exclusively in football games throughout the country at the high school level and below where microphones are not available to the refs.

However, you, the Suze, are not at a high school game, and you are not the coach on the sideline (although I would absolutely LOVE to see that).  So why do you need to see the hand signals? Tradition, plain and simple.