Some restaurant kitchens feature drawings of each table, with staffers constantly updating tables' happiness levels on a 1-10 scale. There aren't drawings at theaters but rest assured that actors monitor happiness levels.
"We talk about the audience constantly backstage. Constantly," said Sun Mee Chomet, appearing now in the Guthrie Theater's "Sally & Tom" and from Nov. 20-Dec. 23 in Jungle Theater's "Georgiana & Kitty."
Sometimes, it's gossip. But it might also be about adjustments to make for an audience that's inclined to clap longer than usual.
"We'll say, 'Did you hear that guy with the big laugh?' We're always talking, between scenes and at intermission, about the audience as an entity and the energy we're getting back from them," Chomet said.
The pact formed by audiences and theaters is often spoken of as sacred because the exchange only works when both are fully engaged. That's why actor/director Joseph Papke, who's also the founder of Classical Actors Ensemble — which opens "Othello" Oct. 28 at Elision Playhouse — has developed a rule about audience responses. He believes the maxim that "the customer is always right" holds true for theater.
"When rehearsing comedies, we think whatever we've come up with is great," said Papke. "But if it doesn't get laughs, the rule I go by is if you do it in front of an audience two times and it still doesn't get a laugh, cut it or change it. It's a losing battle, otherwise."
There's no right or wrong amount of applause but actors learn to gauge it so they're not drowned out by laughter or clapping.

"Applause is like a wave, or an arc," said Adán Varela, who was in Theater Latté Da's "Twelve Angry Men" this summer and currently understudies several roles in "Carmela Full of Wishes" at Children's Theatre Company. "A laugh, too. It'll go up and up, usually, and when it starts to go down, it's time to come in."