Crosslinguistic Study of Vowel Discrimination

The objective of this experiment is to compare the identification and discrimination of a series of rounded and unrounded vowels by Swedish and American English listeners. All stimuli were produced with the OVE II synthesizer at the Royal Institute of Technology in Stockholm. The unrounded vowels are in the phonemic system of both Swedish and American English, and encompass the three vowels /i/, /ɪ/, and /ɛ/. The rounded vowels encompass the Swedish vowels /i/, /y/, /u/, but are not in the phonemic system of American English. Each series consists of 13 vowels, for which the first three formant frequencies vary in approximately equal logarithmic steps through the indicated range. By discrimination tests showed that both series of vowels gave essentially identical discrimination data for both groups of listeners. Identification functions for the unrounded vowels were similar for the two groups of listeners, but American English listeners were less consistent than Swedish listeners in the identification of the rounded vowels. Implications of the results with regard to theories of speech perception are discussed. [This study supported in part by the National Science Foundation.]