Does one plus one equal three in early simultaneous bilingual speech perception?

Abstract

Over half the world’s population is bilingual, yet we know little about organization of phonetic abilities in early simultaneous bilinguals. In this study we tested bilingual French–English adults who had learned and used both languages simultaneously since birth. They were presented dental and alveolar stop consonants excised from real-word productions of French /t/ and English /d/, selected to insure that VOT values overlap. The alveolar-dental place distinction is not phonemic in either French or English. However, bilingual individuals are systematically exposed to this place distinction across their two native languages. Recent findings [Sundara and Polka, J. Acoust. Soc. Am. 110, 2685 (2001)] indicate that simultaneous bilinguals clearly produce this place distinction. Perception was assessed using a categorical AXB task with tokens produced by multiple talkers in both French and English. Assimilation data were also obtained using a keyword identification task in both languages. Performance of bilinguals was compared and contrasted with those of respective monolingual groups and with native Malayalam listeners (dental-alveolar distinction is phonemic in Malayalam). The findings provide insights into perceptual organization in simultaneous bilingual adults by addressing whether an emergent contrast, not evident in either monolingual group is observed in both perception and production of bilinguals.