Beschreibung:
<jats:p>Young infants discriminate most native and nonnative phonetic contrasts. Adults, however, often have difficulty with nonnative contrasts, as do infants by 10–12 months [Werker, Am. Sci. 77, 54–59 (1989)]. Best et al. proposed that phonological development fosters perceptual assimilation of nonnative contrasts to the most similar native phoneme(s), according to four possible patterns [J. Exp. Psychol.: Human Percept. Perf. 14, 345–360 (1988)]: (1) Both phones assimilate to a single category (SC); (2) they differ in category goodness (CG); (3) they assimilate to two categories (TC); or (4) they are nonassimilable (NA). Only SC contrasts should pose difficulty for phonologically sophisticated listeners. Recently, however, 10–12 month olds failed to discriminate nonnative CG and TC contrasts, which were discriminated by adults and younger infants [Best, Int. Conf. Infant Studies (April 1990)]. The present study examined further perceptual development in 4 year olds, who discriminated a native control contrast and the CG contrast, but not the TC contrast. Two possible explanations will be discussed: (1) still-immature perception of phonological contrast; or (2) specific difficulty with the fricative voicing feature employed in the TC contrast. In either case, the results suggest that 4 year olds do not yet show mature phonological assimilation. [Work supported by NIH Grant DC-00403.]</jats:p>