A lip-reading recognition accuracy score of 45% correct places an individual 5 standard deviations above the mean. These results quantify the inherent difficulty in visual-only sentence recognition.

What percentage of lip reading is accurate?

In an earlier paper, Oxford computer scientists reported that on average, hearing-impaired lip-readers can achieve 52.3 percent accuracy. Meanwhile, Georgia Tech researchers say that only 30 percent of all speech is visible on the lips.

Why is lip reading not reliable?

Another challenge of lip reading is that many things obstruct the visual cues — from accents, to hand gestures, to speed, and mumbling. ... However, while lip reading is difficult, Kolb stresses that when locking onto a face, it creates a unique sense of "human connection."