Assessing Visual Speech Communication Abilities: Cross-situational Consistency in Lipreadability

Objective: Does the accuracy with which an individual can receive visual speech information reflect one psychometric ability while the accuracy with which they can transmit visual speech information reflect a different ability? This question has not been directly addressed in previous studies, but if so, it would have important theoretical, methodological, and clinical implications because of the interaction between the accuracy of auditory and visual speech recognition in noisy situations. From a psychometric perspective, an ability is distinguished by a high degree of cross-situational consistency in the pattern of individual differences. Therefore, the present investigation focused on whether individuals were consistently good or bad at recognizing vision-only speech as well as whether they were consistently good or bad at accurately transmitting visual speech information. Design: Round-robin experimental designs, in which each participant in a group lipreads everyone else in their group, provide an efficient way to simultaneously measure individual differences in the consistency in individuals’ lipreading accuracy across talkers as well as the consistency with which different senders (i.e., talkers) transmitted accurate speech information to different receivers (i.e., lipreaders). Accordingly, the present investigation analyzed data from two groups in a round-robin study in order to assess the degree of consistency in both lipreading ability (i.e., the accuracy with which different participants lipread others in their group) and lipreadability (i.e., how accurately individual talkers could be lipread by the others in their group). Results: In both groups, very strong correlations (mean rs = .867 and .897) among the accuracy with which different individuals’ lipread different talkers demonstrated that the same individual participants were consistently good (or poor) at lipreading regardless of who the talker was. Consistent with the hypothesis that the ability to transmit visual speech information is also a psychometric ability, additional strong correlations (mean rs = .645 and .842) revealed that in both groups the same individual talkers were consistently lipread accurately or inaccurately regardless of who was doing the lipreading. There was no evidence that participants’ lipreadability (production) was related to their l.lipreading ability (comprehension).Conclusions: The present findings show that the effectiveness of visual speech communication depends on two separate psychometric abilities: receivers’ lipreading ability and senders’ lipreadability. Together, these abilities determine the accuracy with which speech information is communicated from senders to receivers, particularly in noisy situations, and the degree of communication possible between a specific sender and a specific receiver of speech information. In other words, in some situations what people describe as ‘hearing problems’ might be better described as problems with audiovisual communication. Identification and assessment of the specific nature of these problems may make it possible to more accurately target and potentially remediate the communication problems people experience in everyday life.