Maybe a command word or signal you could train to that Master can use to tell you when you are 'speaking out of turn'. It could be a word (your name in a certain tone of voice) or a sound 'a sharp 'ah ah' noise is often used to tell dogs when they are doing something naughty) or a non verbal thing (a tap on the shoulder, a sign he makes with his hands or fingers, a stern glance, a shake of the head). If the sign is made you stop whatever you are doing or saying and await his command, being unable to take any action or speech until he gives permission. Disregarding the sign means punishment at an appropriate time (immediately if in a scene friendly place, at home if not).

This should allow you to express yourself while also giving him control over your extroverted actions.