Additive effects of phonetic distinctions in word learning

Abstract

While infants have been demonstrated to be sensitive to a wide variety of phonetic contrasts when tested in speech discrimination tasks [Eimas et al. (1971) et seq.], recent work [Stager and Werker (1997)] has shown that following habituation to a word–object pairing, infants of 14 months fail to notice when the place of articulation of the initial consonant is switched [b/d]. Using the same procedure, the present study has found that infants do not respond to a change in voicing [b/p]. They do, however, notice a switch between dissimilar words [lɪf/nim]. One interpretation of these findings is that 14-month-olds do not encode either place or voice distinctions in lexical representations, so that words differing in only these features are treated as identical. To test this hypothesis, the effect of combining featural contrasts is currently being investigated by examining whether infants do respond to a change in both place and voice [d/p]. If there is such an additive effect, the contrasts must be represented. This would entail that an explanation for the failure to distinguish words differing in only a single feature should invoke processing factors, rather than representational ones.