Many people assume Deaf and hard-of-hearing people read lips. This is a common misconception. It is estimated that only 30% to 40% of speech sounds can be lip-read even under the best conditions and extra information is usually required to understand what is being said. So while it can be an important skill for people with a hearing loss to have, relying on lip-reading alone will not be enough for someone to develop good communication skills (NCDS).
Is Lip Reading Effective?
Due to the limited amount of speech that can be understood by lip reading, this makes it very hard for a Deaf person to correctly read the speaker’s lips. This is because many words cannot be differentiated as they have the same lip pattern. For example: words that sound the same and have different meanings, but look the same on the lips e.g. which / witch, or break / brake. There are many of these in the English language. Knowing the topic of conversation first helps the lip reader here. Words that sound different and have different meanings, but look the same on the lips e.g. gap / cab / ham. Try mouthing these words to yourself now and notice how you make the same lip pattern for each. Another example is mad / ban / mat (hearingdogs.org).
Also, facial hair, such as goatees, mustaches, and beards, make it harder to see someone's lips. During these times of Covid, it is hard to see peoples mouths while they wear masks.
Again, only about 30% to 45% of the English language is discernible through lip reading, while contextualization and guessing determine the remainder (Barnett, 1999, 2002a, 2002b; Ebert & Heckerling, 1995; Iezzoni et al., 2004; Margellos-Anast et al., 2005). Lip reading ability also varies and is influenced by such things as poor lighting, distance from the speaker, difficulty seeing the speaker's face, or limited familiarity with the speaker's speech patterns (medscape.com).
Resources To Learn More:
National Deaf Children's Society (NDCS): https://www.ndcs.org.uk/information-and-support/language-and-communication/spoken-language/supporting-speaking-and-listening/lip-reading
Hearing Dogs for Deaf People: https://www.hearingdogs.org.uk
SIGN Academy Blog: https://www.mysignacademy.com/blog