Here is a not unusual scenario from lower-level classes.
Before getting students to work on a task in pairs, teachers often model a few questions by asking a few students in the class to answer. The teacher expects students to listen to these questions, and to be ready to answer when they're called on. For my example, the teacher is asking, "What time do you _____?" She's filling in the blank with various everyday activity verbs. Watch her run into a bit of trouble with the second student:
Teacher: What time do you go to sleep? Rika.
Rika: 1 AM
Teacher: Full sentence, please?
Rika: I go to sleep at 1 AM.
Teacher: Thanks. Next question. What time do you wake up? Kenji.
Teacher: Answer the question, please.
Kenji: Mo ikai [Japanese for "Once more"]
Teacher: Once more?
Kenji: hai, yes, once more.
Teacher: What time do you wake up?
Kenji: Yes, I do. ... Yes, I am.
OK, so Kenji wasn't paying attention at all. This scenario is actually pretty realistic for some of the teaching situations I've worked in. I can recall more than a few times when the "Kenji" student was actually the fifth student to be called upon. In short, there are some students who simply won't pay attention until they're held personally responsible for doing so. (Have you ever asked a student to answer a question, and watched as they then put on glasses to squint at the board for hints about what was happening?)
Teacher: [writes on board: A, around 9. B, around 11. C, around 1 AM. D, very late.] What time do you go to sleep? What's your best answer? What time do you go to sleep? 3,2,1, answer.
Students all show their Captur paddles
Teacher: Kenji, you didn't answer. Someone help Kenji. OK, so a lot of people showed me "C". I saw a few "B" and "D" but no "A" answers.
This can warm up the students for asking each other and answering in sentences or short answers, as usual. The difference is, every student listens to every question. Every student pays attention to every question, then evaluates those questions so that they can choose the answer that is closest to her own answer. This activity is one that isn't very different from what this teacher is already comfortable with. This teacher hasn't really had to change her teaching style at all for this, and already she can see that students are paying more attention to the language that they're exposed to.
This article is a made-up comparison of two scenarios, but both scenarios are based on real experiences in actual classrooms. Students cannot learn if they're not attentive to what's going on. Many of my students turn out to be much more attentive when they know they're accountable.