Language-specific restrictions on sound sequences in words can lead to automatic perceptual repair of illicit sound sequences. As an example, no Spanish words begin with /s/-consonant sequences ([#sC]), and where necessary (e.g., foreign loanwords) [#sC] is repaired by inserting an initial [e], (e.g. foreign loanwords, cf., esnob, from English snob). As a result, Spanish speakers tend to perceive an illusory [e] before [#sC] sequences. Interestingly, this perceptual illusion is weaker in early Spanish-English bilinguals, whose other language, English, allows [#sC]. The present study explored whether this apparent influence of the English language on Spanish is restricted to early bilinguals, whose early language experience includes a mixture of both languages, or whether later learning of second language (L2) English can also induce a weakening of the first language (L1) perceptual illusion. Two groups of late Spanish-English bilinguals, immersed in Spanish or English, were tested on the same Spanish AX (same-different) discrimination task used in a study by Carlson et al., (2016) and their results compared with the Spanish monolinguals from Carlson et al.'s study. Like early bilinguals, late bilinguals exhibited a reduced impact of perceptual prothesis on discrimination accuracy. Additionally, late bilinguals, particularly in English immersion, were slowest when responding against the Spanish perceptual illusion. Robust L1 perceptual illusions thus appear to be malleable in the face of later L2 learning. It is argued that these results are consonant with the need for late bilinguals to navigate alternative, conflicting representations of the same acoustic material, even in unilingual L1 speech perception tasks.
Keywords: Speech perception; bilingualism; perceptual illusion; phonotactics.