Read my lips - Advances in speechreading research with deaf children
11 May 2013
Speechreading is the term used by researchers to refer to lipreading. ‘Speechreading’ is preferred to ‘lipreading’ because lots of information is used from all of the face, not just the lips, when you watch someone speak. For deaf people, this can be their primary route to speech information. Hearing people also make great use of visual speech, although they often don’t realize it. If you think of talking to someone in a noisy bar, a hearing person is much more likely to understand a person if they can be seen. This is where the old joke ‘I can’t hear you without my glasses on’ comes from.
DCAL researchers have previously developed a Test of Adult Speechreading (TAS; Mohammed et al., 2006). This computerised test was specially designed for deaf adults and did not require any reading or writing responses, unlike many previous tests. Deaf adults (18-60yr olds) performed better than hearing adults on this test. In addition, how well deaf people performed on the speechreading test was correlated with their reading skill.
Now, DCAL researchers have developed a similar test for children: the Test of Child Speechreading (ToCS). A total of 86 deaf and 91 hearing children were tested aged between 5 and 14 years. Children were assessed at different levels: single words, sentences and connected speech. The researchers found that unlike adults, deaf and hearing children had similar levels of speechreading skill. This pattern suggests either a decrease in speechreading skill in hearing children after the age of 14 years relative to deaf children, or, more likely – that as deaf people get older and go through adolescence and into early adulthood – their speechreading skills improve with greater practice and reliance on visual speech, relative to hearing people. Further research is needed on the age group not yet tested by the TAS and the ToCS (14-18 year olds) to find out what happens to speechreading skills in this stage of development.
The research with children also demonstrated, just like the adult data, that there was a positive correlation between speechreading and reading skill. This was found not only in deaf children, but interestingly, also in hearing children.
Further research is planned by the team to further examine the relationship between speechreading and reading in deaf children.
A copy of the research – to be published in the Journal of Speech, Language and Hearing Research - can be requested from Dr Mairéad MacSweeney.