Lipreading with auditory low-frequency information. Contextual constraints

The present experimental study investigated potential relations among three variables: (1) an audiovisual speech signal (i.e., low-frequency supplemented lipreading as opposed to pure lipreading), (2) typical, as opposed to atypical, sentences in a particular script (e.g., in a restaurant), and (3) the presence/absence of additional context (in the particular script) in 60 normal hearing subjects. All three variables revealed significant main effects, but no interactions were observed. The general facilitatory effect for the audiovisual signal is in line with previous research, but this effect was relatively weak compared to the main effect of typicality, which relies on cognitive activation of scripts. In a separate analysis, the typicality variable was also the only variable that interacted significantly with speechreading skill, typical sentences being perceived relatively easier by the skilled as opposed to the less skilled individual. The clinical implications of cognitive factors in hearing-aid fitting procedures, the construction of speech materials, and selection of individuals for rehabilitation were discussed.