Feedback is an output information of the performance of anything.
The gestures given in the question are examples of non-verbal communication. Non-verbal communication is communication that is not communicated through mouth or by words but by body language or gestures.
<u>The given list in question are all forms of feedback from the audience. When an audience listens to the speaker they give non-verbal feedback by making eye contact, nodding their heads on the points they agree with, even facial expressions of the audience is a form of feedback</u>.
So, all elements of the list in the question are a form of feedback.
