Adults look at the eyes of faces in seek of social information (Yarbus, 1967). However, when the auditory information becomes unclear (e.g. speech-in-noise) they switch their attention towards the mouth of a talking face and rely on the audiovisual redundant cues to help them process the speech signal (e.g., Lansing & McConkie, 2003). Recent developmental studies on selective attention suggest that infants also take advantage of the audiovisual speech cues by resourcing towards the talker’s mouth during the onset of babbling (Lewkowicz & Hansen-Tift 2012) and also to aid language differentiation in the case of bilingual infants (Pons, Bosch, & Lewkowicz, 2015). Here I will present a set of studies that provide a more detailed examination of the audiovisual (AV) speech cues contribution to speech perception and processing at different language development stages, through the analysis of selective attention patterns when processing speech from talking faces. To do so, I will compare different language factors that modulate audiovisual speech perception in both first language/s acquisition during early childhood and in second language acquisition during adulthood.