Feedback signals and hand signals are non-verbal signals used to help run group management. It was originally introduced in Kagan's cooperative structures to check for comprehension. It helps facilitators and in our case, the teacher, to see emerging results and immediate feedback. Some teachers told me isn't that against the idea of cultivating the communicative skills. The TL is used when teachers have given a task and wants to know whether all students understand the task- immediate feedback from all. Or after explaining a concept, the teacher may use TL. TL gives a voice to each child, especially those who might be too shy. Every time a teacher asks whether students understand, there will be a few who might be too afraid to say anything.When all students are required to use the TL, everyone has a chance for their learning to be more effective. No where should it be used to replace communicative activities.
For a class with only two students, I guess you might not need quiet signal or TL but in my observations in the classroom, students enjoy using it.
THE QUIET SIGNAL
According to Kagan's research, we lose 18 days requesting our students to keep quiet. I sometimes see teachers stuggling, shouting "Listen, listen, listen!" The goal should be to obtain silence and attention within 5 seconds. Hence, the need for the quiet signal. It is not about not giving the chance for students to speak. There is a time for everything in a classroom. If teachers cannot command the attention of the students when they are in groups, it would be tiring for the teacher to explain to every group. Some teachers use a chant to gain attention, some use "High Five" or 'Give me five".