The focus for our Performance Management reviews this year is literacy: one focus is speaking and listening.
One technique used is the fist of five for immediate feedback: usually 5 indicates full understanding with the ability to explain to the class, while 1 indicates absolutely no idea. Students usually range from 2 to 4 (with a flicking finger indicating a half!)
My colleague recently used this to great effect in a maths lesson where she paired the 4s to teach the 2s to learn and reinforce in equal measure. It was a short exercise that worked extremely well, and is clearly an outstanding example of directing speaking and listening to aid learning.