Camillia Bouchon, Caroline Floccia, Thibaut Fux, Martine Adda-Decker and Thierry Nazzi
It has been proposed that consonants and vowels have different functional roles in language processing and, in particular, that consonants are more important in distinguishing words in the lexicon (Nespor, Peña & Mehler, 2003). Many studies on French provide convrgent support for this proposal in adulthood and toddlerhood (Havy & Nazzi, 2009; Nazzi, 2005; New et al., 2014). We investigated the relative importance of consonants and vowels at the onset of lexical acquisition in French-learning 5-month-old infants. Reactions to mispronunciation in their own name were compared whether the change was consonantal (e.g. Victor/Zictor, n = 30) or vocalic (e.g. Alix/Elix, n = 30). Behavioral results indicated sensitivity to vowel changes, and not to consonant changes. Detailed acoustic analyses of THE stimuli revealed that vowels were more salient but spectrally less distinct than consonants. Lastly, vowel (but not consonant) mispronunciation detection was modulated by acoustic factors, in particular by the spectrally-based distance. This shows that the consonant bias for lexical processing observed later in development does not emerge until after 5 months of age through additional language exposure.