Newborn infant perception of vowels is affected by ambient language.

Abstract

Behavioral research has shown that by 6 months of age, infants show an effect of experience with native language vowels. In a previous study of category organization, infants in Sweden and the United States treated a vowel prototype as equivalent to variants of the vowel in the native, but not the non‐native language. In the current behavioral study of Swedish and U.S. neonates, results were consistent with those of the 6‐month‐olds. Eighty infants (M=32.8 h since birth) in Washington State and Stockholm participated in a procedure in which non‐nutritive sucking activated one of 17 stimuli (a prototype and 16 variants) from the same vowel category. Twenty infants in each country heard their native vowel, and 20 the non‐native vowel. The vowels were English /i/ and Swedish /y/. Stimuli were serially and randomly activated by the onset of a sucking bout, and once a stimulus was activated, frequency of presentation was infant‐controlled. The dependent measure was number of sucks for each stimulus. For the non‐native vowel only, the mean number of sucks was significantly higher for the prototype than the mean for the 16 variants. This suggests that category organization of vowels begins in utero.