In this article, we show that the generative phonological distinction between lexical and surface representation can explain apparently contradictory orders of acquisition of L2 voice and aspiration contrasts by native speakers of English. Cross-language speech perception research has shown that English speakers distinguish synthetic voice onset time counterparts of aspirated–unaspirated minimal pairs more readily than voiced–voiceless. Here, we present evidence that in the perceptual acquisition of the same Thai contrasts, English speakers acquire voicing before aspiration. These divergent orders are argued to be due to the levels of representation tapped by the methodologies employed in each case: surface representations in the earlier studies, and lexical in the present one. The resulting difference in outcomes is attributed to the presence of aspiration in surface, but not lexical, representations in English (Chomsky and Halle, 1968). To address the further question of whether allophonic aspiration in English aids in the eventual acquisition of contrastive aspiration in Thai, we compare the developmental progression of the English learners to that of native speakers of French, whose L1 contains only a voicing contrast, and no surface aspiration. The performance of the anglophone group improves over time, suggesting that L1 surface features can be lexicalized in L2 acquisition,even though they are not initially transferred across levels.

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.