Today I am lighting a candle for a dear friend of mine, Consuelo, who passed away from cancer two years ago. Consuelo was also deaf, like me. I am thinking a lot about her today and our friendship. Really, I could wax poetic about our friendship and how much she meant to me, but instead I really want to highlight her important contribution to a widespread misconception:
The best lipreaders who are deaf can only understand 30 percent of the spoken word.
Here is her eloquent response to this. I could not have said it any better. Thank you, Consuelo, for your astute analysis and efforts to debunk this myth.
[This is] not true. The fact is that any speechreader [another term for lipreader], in any instance, will understand anywhere from 0 to 100 percent of what is said, depending on the circumstances. There is no statistic or percentage regarding comprehension that can be applied to all speechreaders, in all situations. [Elizabeth note: Circumstances include: how tired one is feeling, the noise and lighting level in the room, how many people there are, if there is an accent, etc etc]
So, where does this “30 percent fact” come from?
This so-called “fact” is a fascinating urban myth that has spread with the increased use of the Internet and World Wide Web, and with the relaxed documentation of sources.
During the 1950s, a study was conducted at the John Tracy Clinic in Los Angeles, California. In the study, speech pathology students — all with normal hearing — were asked to lip-read isolated phonemes (isolated vowels or consonants of the English language such as “sh,” or “oo,” or “r”). Of those phonemes, these students were able to correctly identify (through visual cues alone) approximately one-third. The finding of the study was that, in general, no more than about one-third (or “30 percent”) of the individual phonemes of the English language are visible on the lips.
It’s important to note that this study made no measurement of and no claims regarding the comprehension abilities of speechreaders, and that speechreaders do not read individual phonemes, but whole words in the context of sentences.
By the 1970s, the “30 percent fact” began appearing in print, but it had now been changed (either mistakenly or deliberately) to the erroneous claim that “even the best speechreaders can understand no more than 30 percent of what people say using speechreading alone.” Other percentages have variously been claimed, however, regardless of the percentage, any such claim is a distortion of the original study’s finding, which had nothing to do with speechreading.
Over the past 30-plus years, hundreds of books and articles have included such erroneous claims as fact, many of which can now be found on the Internet.
In 2002, Daniel Greene, a student at National University, conducted an extensive Internet research project on this very topic*, in which he contacted the writers and editors of scores of articles that included a claim that speechreaders can understand no more than “X percent” of the spoken word. Not one of them could identify what their specific source for the claim had been. This is not surprising, as there is no source to support it — the original study made no such claim.
* From unpublished research paper, “Collective Truths: Unquestioned Statistics Regarding Speechreading” December 2002, Daniel Greene