• Background information--

In the exposition of the novel No Talking, the main character, Dave Packer, has been affected by what he has read about Mahatma Gandhi, who would not speak at all on one day a week, believing that this was a way to bring order to his mind.  Perhaps, Dave considers, if he practices being quiet, he might do better in his studies. So, he decides to practice silence one day at Laketon Elementary School. 
At lunch in the cafeteria, when Dave hears a classmate named Lynsey loquaciously describing her shopping trip, he becomes annoyed. He shouts at her, claiming her head would explode if she had to be quiet for a few minutes. Lynsey takes this as a challenge and they agree that for two days their entire class will say no more than three words at a time, nor will they talk at home. In a sense, Dave and Lynsey become team captains and keep tallies of anyone who breaks the rules. 

• In Chapter 15--

Mrs. Hiatt, the principal, has a meeting with the teachers in which they discuss the uncharacteristic silence of the fifth graders to whom the teachers have given the moniker "The Unshushables." At this meeting Mrs. Hiatt listens to the opinions of the teachers. It is interesting how the teachers respond to the fifth graders' acts of silence as their classes are affected differently depending upon the academic discipline that they teach.

• The math teacher, Mrs. Escobar, says that being quiet is a game to the class.
• The English teacher, Mr. Burton, feels that being silent in competition is inventive and creative because it allows the students to think and devise alternative ways to express themselves, such as in writing.
• The Physical Education teacher, Mrs. Henley, declares that the students' silence is no problem; in fact, this silence eliminates their complaining.
• The Music teacher, Mrs. Akers, complains that she cannot teach students songs if students refuse to sing. She adds that the Art teacher, Jim Torrey, concurs with her opinion that the silence is counterproductive.

Mr. Burton interrupts, reminding the teachers that the class they speak of is the same group called the Unshushables. He suggests that they be patient a few days and not "start them back up." Of course, he has a personal interest in the students' behaviors because he is composing a study on the students' alternative communication methods for a Human Development course he is taking.

When the teachers display a growing disagreement with each other, the principal intervenes, thanking the teachers for their input. Further, she explains that the situation is not one that calls for a vote; she has made her decision. She explains that while it is tempting to go along with the students' being silent, neither their game of silence nor their usual talkativeness are acceptable behaviors. The students need to learn the appropriate times to be quiet and to speak, not arbitrarily choose their own times. 
She adds that she thinks that Dave and Lindsey are the ringleaders, but Mrs. Marlow interjects, "I think it's more like Dave and Lindsey are sort of team captains." Mrs. Marlow explains that the boys are against the girls and are keeping score because she has intercepted a note. Mrs. Hiatt is rather displeased that Mrs. Marlow has not told her this information. Then, Mr. Burton asks what action Mrs. Hiatt will take if the students do not respond to her instructions at the assembly. So, Mrs. Hiatt promises that she will do what she can to resolve the situation.
Interestingly, the teachers leave the meeting in a silence not unlike that of the fifth grade students. Perhaps, they, too, have discovered a significance to silence.