Perception of Japanese Pitch Accent without F0

Abstract

Phonological contrasts are typically encoded with multiple acoustic correlates to ensure efficient communication. Studies have shown that such phonetic redundancy is found not only in segmental contrasts, but also in suprasegmental contrasts such as tone. In Japanese, fundamental frequency (F0) is the primary cue for pitch accent. However, little is known about its secondary cues. In the present study, a perception experiment was conducted to examine whether any secondary cues exist for Japanese accent. First, minimal pairs of final-accented and unaccented words were identified using a database, resulting in 14 pairs of words. These words were then produced by a native Tokyo Japanese speaker, and presented to participants in both unedited and edited forms. Edited speech stimuli were created by replacing F0 in the natural speech stimuli with white noise. While word identification by Tokyo Japanese speakers had higher accuracy for natural speech than for edited speech, the accuracy exceeded the chance level for edited speech, suggesting the existence of secondary cues for Japanese accent. Acoustic analysis of the stimuli revealed that relative mean amplitude and relative maximum amplitude were greater for final-accented words than for unaccented words.