Individual differences and the acquisition of new phonetic categories

Abstract

Adults’ acquisition of non-native phonetic categories occurs within the context of an individual’s existing phonology. The present work examines (1) the process of acquiring a new phonetic category, (2) the impact of the new phonetic category on nearby, previously existing categories, and (3) transfer of learning to novel contexts. Monolingual American English speakers were required to learn the Hindi voiced, unaspirated, dental stop consonant. First, listeners were asked to identify and judge the goodness of stimuli on two synthetic continua spanning a range from Hindi dental to American English alveolar stop consonants. One continuum was voiced, the other voiceless. In addition, listeners judged the similarities between all possible pairs of stimuli on each continuum. After this perceptual mapping procedure, subjects participated in a two-alternative, forced-choice training program using only voiced stimuli. Progress was monitored throughout training. Following training, the mapping procedure was repeated with both the voiced and voiceless continua. Results are discussed from the theoretical perspective of the nonlinear dynamical approach to learning and transfer in motor behavior presented by Zanone and Kelso [in Swinnen, Heuer, Massion, & Casaer, 461–490 (1994)] and with respect to Best’s perceptual assimilation model and Kuhl’s perceptual magnet effect. [Work supported by NIDCD and NIMH.]