From Perceptual Learning to Speech Production: Generalizing Phonotactic Probabilities in Language Acquisition

Phonotactics are the restrictions on sound sequences within a word or syllable. They are an important cue for speech segmentation and a guiding force in the creation of new words. By studying phonotactics, we stand to gain a better understanding of why languages and speakers have phonologies. Through a series of four experiments, I will present data that sharpen our theoretical and empirical perspectives of what phonotactics are and how they are acquired.The methodology is similar to that used in studies of infant perception: children are familiarized with a set of words that contain either a few or many examples of a phonotactic sequence. The participants here are four-year-olds, and the test involves producing a target phonotactic sequence in a new word. Because the test words have not been encountered before, children must generalize what they learned in the familiarization phase and apply it to their own speech. By manipulating the phonetic and phonological characteristics of the familiarization items, we can determine which factors are relevant to phonotactic learning. In these experiments, the phonetic manipulation was the number of talkers who children heard produce a familiarization word. The phonological manipulation was the number of familiarization words that shared a phonotactic pattern.The findings include instances where learning occurs and instances where it does not. First, the data show that the well-studied correlation between phonotactic probability and production accuracy in child speech can be attributed, at least partly to perceptual learning, rather than a practice effect attributable to repeated articulation. Second, the data show that perceptual learning is a process of abstraction and learning about those abstractions. It is not about making connections between stored, unelaborated exemplars because learning from the phonetic manipulation alone was insufficient for a phonotactic pattern to generalize. Furthermore, perceptual learning is not about reorganizing pre-existing symbolic knowledge, because learning from words alone is insufficient. I argue that a model which learns abstract word-forms from direct phonetic experience, then learns phonotatics from the abstract word-forms, is the most parsimonious explanation of phonotactic learning