The effect of seeing the interlocutor on auditory and visual speech production in noise

Talkers modify their speech production in noisy environment partly as a reflex but also as an intentional communicative strategy to facilitate the transmission of the speech signal to the interlocutor. Previous studies have shown that talkers can adapt both auditory and visual elements of speech produced in noise. The current study examined whether auditory and visual speech production would be affected by being able to see their interlocutor or not. Participants completed an interactive communication game in various quiet and in noise conditions with/without being able to see their interlocutor. The results showed that the amplitude of talkers' speech modifications was significantly lower when interlocutors could see each other. Furthermore, talks instead increased the saliency of their visual speech production (measured as lip-area) in noisy conditions for face-to-face communication. These results suggest that talkers actively monitor their environment and adopt appropriate speech production for efficient communication.