Effects of consonantal context on the learnability of vowel categories from infant-directed speech

Recent studies have shown that vowels in infant-directed speech (IDS) are characterized by highly variable formant distributions. The current study investigates whether vowel variability is partially due to consonantal context, and explores whether consonantal context could support the learning of vowel categories from IDS. A computational model is presented which selects contexts based on frequency in the input and generalizes across contextual categories. Improved categorization performance was found on a vowel contrast in American–English IDS. The findings support a view in which the infant's learning mechanism is anchored in context, in order to cope with acoustic variability in the input.