Investigating the impact of lip visibility and talking style on speechreading performance

Highlights? We explore the impact of lip visibility and speaking style on speechreadability. ? We compare speechreading from talkers with natural, bright and concealed lips. ? Highlighting the lip area by lipstick or concealer improves speechreading. ? Speaking in a clear (rather than conversational) manner improves speechreading. ? Results are discussed in practical terms and in relation to attention and movement. It has long been known that visual information from a talker's mouth and face plays an important role in the perception and understanding of spoken language. The reported experiments explore the impact of lip visibility (Experiments 1 & 2) and speaking style (Experiment 2) on talker speechreadability. Specifically we compare speechreading performance (words in Experiment 1; sentences in Experiment 2 with low level auditory input) from talkers with natural lips, with brightly coloured lips and with concealed lips. Results reveal that highlighting the lip area by the application of lipstick or concealer improves speechreading, relative to natural lips. Furthermore, speaking in a clear (rather than conversational) manner improves speechreading performance, with no interaction between lip visibility and speaking style. Results are discussed in relation to practical methods of improving speechreading and in relation to attention and movement parameters.