Silence is Golden...
These fish normally feed in schools and experienced fishermen will stay extremely silent when they chance upon a school of Snapper. This gives them a chance to pull in a good number of Snapper before the bites 'turn off'.
Inexperienced fishermen, on the other hand, would not be able to handle a fish properly, letting it flop around the boat, or they would talk very loudly, turn on a radio (or even a portable TV), do a victory dance, and do everything to prevent anyone else, including themselves, from catching any more fish. (I have to admit that I too, have been guilty of some of the above crimes... heehee... but numerous hard lessons have taught me well.)
As we all know, Snapper are highly sensitive to sound and even the smallest lead weight dropped carelessly in a boat might ruin a whole day's fishing as these fish are only 'turned on' for brief moments in a day. Thus, turning them off the moment they start biting could be disastrous, not only for you, but also for everyone else on the boat.