Articulatory effects of frequency modulated by inflectional meanings

In this paper, we discuss three studies. In the first study, we replicated the phonetic enhancement effect of frequency using ultrasound. While this study supported the hypothesis of paradigmatic signal enhancement by higher frequency (or probability), it was also contradictory to the studies that found phonetic reduction effects of frequency. To reconcile this contradiction, in the second study, we investigated the effect of frequency in interaction with morphological status. The result showed that higher frequency was associated with phonetically reduced realizations for non-inflected words, while phonetic enhancement was observed for inflected words. Subsequently, in the third study, we explained the enhancement effect of frequency in terms of semantic support from words' meanings to their forms.