How much English can be lipread?

Lipreading can enable individuals to understand a significant portion of spoken English, but its effectiveness varies widely among individuals. On average, lipreaders can comprehend about 30% to 40% of spoken dialogue, as many phonemes look similar on the lips and context plays a crucial role in interpretation. Factors such as the speaker's clarity, the presence of visual cues, and the lipreader's experience can greatly influence comprehension levels. Overall, while lipreading can aid communication, it is often not sufficient on its own for full understanding.