Interaction of Frequency and Inflectional Status: An Approach From Discriminative Learning

High frequency of occurrences has been associated with phonetic reduction, on one hand, and phonetic enhancement, on the other hand. This study first looks into the possibility that these opposite frequency effects are at least partially due to the different inflectional status of the items being investigated. Based on tongue position data from a spontaneous speech corpus of German, we found that stem vowels in inflected words tended to be hyper-articulated (i.e., phonetic enhancement), whereas those in non-inflected words tended to be articulated with more centralized tongue positions (i.e., phonetic reduction). This observed modulation by inflectional status is subsequently investigated from the perspective of distributional semantics. Using the discriminative lexicon model to study relations between word embeddings and word forms, we observed that word-final triphones of inflected words received more support from their embeddings (i.e., meanings) compared with non-inflected words. Furthermore, replacement of the two-level factorial predictor of inflectional status with the amount of semantic support led to substantial improvement in model fit. These results suggest direct relationships between word forms and meanings and argue for further investigation of form-meaning isomorphies and their consequences for cognitive models of speech production.