Language Acquisition, Visual Clues

From a Canadian science podcast:

new work builds on [the innate basis for language differentiation by infants], showing that small children can tell apart different spoken languages just by looking at the speaker's face (CBC Radio | Quirks & Quarks | May 26, 2007)

As phonological repertoires served as an inspiration for some early work in cultural anthropology, we could reflect on repertoires of facial expressions as part of enculturation.
One interesting part of the study is that infants from monolingual and bilingual settings differ in the duration of the phase during which they can recognise facial cues for language switches.
Audio interview and relevant links on the Quirks and Quarks website.