if i had to pick one...silence.
"Even a fool who keeps silent is considered wise; when he closes his lips, he is deemed intelligent." Proverbs 17:28
Extended silence, depends on the person. But chatter is meaningless sometimes...
Just recently the Cadillac division of General Motors invented a device that will remove 93 1/2% of all noise from the interior of its' cars. It fits right over her mouth.
I cast one vote for silence.
Ladies constant chatter
Males constant listening