Learning Phonemes Without Minimal Pairs

The question addressed by this research is how humans acquire the internalized, mental categories that reflect the phonemes of their language. That humans have such categories is evidenced by the fact that, for example, English speakers immediately recognize pear and bear as being different words. This immediate realization is independent of the fact that these two words have different meanings, since English speakers will also report that nonsense words like bove and pove are different words – despite the fact that neither word means anything. Phonemic categories, once acquired, have an influence on the perception of speech sounds. Although adults can easily perceive acoustic distinctions that differentiate the categories of their own language, they often have difficulty perceiving non-native phoneme contrasts. For example, the English distinction between /r/ and /l/ is difficult for native Japanese speakers to perceive (Miyawaki et al. 1975), and the Hindi distinction between /t/ and /ţ/ (the latter sound is retroflex, pronounced with the tongue curled backwards) is difficult for native English speakers to perceive (Werker et al. 1981). Infants are born with the ability to categorize speech sounds (Eimas et al. 1971), but these categories are initially universal, not based on the phonemes of a particular language. For instance, Japanese-learning infants can initially discriminate English /r/ and /l/ (Tsushima et al. 1994), and English-learning infants can initially discriminate Hindi /t/ and /ţ/ (Werker et al. 1981). Over the course of the first year of life, though, the infant gains experience with the native language, and begins to only discriminate contrasts that represent a phonemic distinction in the native language (Werker & Tees 1984). Through our research, we would like to understand how these phoneme-related effects on speech perception arise in the language learner.