Interaction of frequency and inflectional status: An approach from discriminative learning

Abstract: High frequency of occurrences has been associated with phonetic reduction on one hand and phonetic enhancement on the other hand. The present study first looks into the possibility that these opposite frequency effects are at least partially due to 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), while 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 Linear Discriminative Learning 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 to 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 imply the necessity of such a structure being considered for speech production models.