Speech reading

December 9, 2015 by Maude Cadieux-Laurin

Lecture labiale

Speech perception is what’s known as a multimodal task—that is, it calls on more than one sense. Combining visual and auditory cues can be a useful and sometimes necessary means of understanding a message.

The term “speech reading” is sometimes used synonymously with “lip reading,” but the former term is the more accurate of the two. That’s because facial expressions, body language, and intonation are all cues that, together with lip movement, help us decode the message.

Who can benefit from speech

Studies show that people with hearing loss have more highly developed lip “reading” abilities. This makes sense, given that they depend daily on visual cues to improve their comprehension and enhance their ability to communicate.

That being said, everyone—from children to adults—uses speech reading on a daily basis without even realizing it. The hearing population generally uses it when auditory cues prove insufficient, for example, when hearing conditions are less than optimal (noisy environments, group situations, and so on) or when the message itself is complex (new words, foreign language, accent).

Are some people naturally better than others at speech reading?

As with any talent or natural aptitude, the ability to speech read varies greatly from one person to the next. Language variation, visual acuity, knowledge of the subject of conversation and the primary language of communication are some of the factors that add to a person’s natural ability to speech read.

Are there ways to get better at speech reading?

Some rehabilitation centres for the hard of hearing offer speech reading classes, which are generally given by speech-language pathologists or audiologists. Studies show that participants in these classes significantly improve their speech reading abilities.

The McGurk effect

The McGurk effect, discovered accidentally in 1970 by Harry McGurk and John MacDonald (two psychologists who were studying how children perceive language at different stages of development), is a phenomenon that demonstrates the multimodality of speech perception. It occurs when a visual cue fails to correspond with the perceived auditory cue.

For example, if the visual cue is a labial phoneme (pronounced by bringing the lips together: “ba”) and the auditory cue is a velar phoneme (pronounced when the tongue comes into contact with the back of the palate: “ga”), we perceive a sound that is a combination of these two cues: a dental phoneme (pronounced by touching the tongue to the back of the teeth: “da”). You’ll find a number of exercises on the Web that illustrate the McGurk effect. It’s a knee-jerk reaction, which tells us that people can’t help but take phonatory mechanisms into
account, even when they try not to!

Sceptical? You won’t know until you try!

References :
JERGER S., M. Damian, N. Tye-Murray and H. Abdi. (2014). « Children use visual speech to compensate for non-intact auditory speech ». Journal of Experimental Child Psychology 126, p. 295–312.
NAHORNA O., F. Berthommier and J. Schwartz. (2012). « Dynamique temporelle du liage dans la fusion de la parole audiovisuelle ». Actes de la conférence conjointe JEP-TALN-RECITAL. (1), p. 481–488.
OLIVEIRA L., A. Soares and B. Chiari. (2014). « Speechreading as a communication mediator ». Universidade Federal de São Paulo 26(1), p. 53-60.
PICOU E, T. Rickettes and B. Hornsby. (2012). « Visual Cues and Listening Effort: Individual Variability ». Journal of Speech, Language and Hearing Research. 54, p. 1416-1430.

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