The correct answer is 30 to 35%.
Even those who are well-skilled at reading lips can only pick up about 30 to 35% percent of what is being said because most of our verbal expression is done inside of the mouth.
When reading lips, it is not only limited to the mouth and tongue to recognize words. You have to pay attention to gestures, body language, and facial expressions. This is true because even the most skilled trained people can only read 30 to 35% of people's lips, and that is the case when the individual has good lip movements.
