Phonetic realization of Japanese vowel devoicing

Abstract

Despite the widely used term “vowel devoicing”, previous studies have reported that the phonetic realization of Japanese devoicing ranges from devoiced vowel to complete vowel deletion, and is often described as deleted or reduced as opposed to “devoiced” (Beckman, 1982; Keating and Huffman, 1984; Tsuchida, 1997; Kondo, 1997; Maekawa and Kikuchi, 2005, Ogasawara and Warner, 2009). The current study presents an acoustic investigation of phonetic implementation of Japanese vowel devoicing to examine the relative likelihood of vowel devoicing, reduction, and deletion. Twenty-four native speakers of Tokyo Japanese produced 80 words containing high vowels in single devoicing environments. The data revealed that the majority of vowel devoicing tokens (>95%) were phonetically realized as vowel deletions, with no trace of devoiced vowels (= energy excited at frequencies of vowel formants with an aspiration source). Given this result, vowel “deletion” may better characterize the phonetic implementation of Japanese devoicing. Theoretical implications of this finding for Japanese phonological structure will be discussed, including an account that considers mora as the fundamental phonological unit at which devoicing takes place and subsequently views devoicing as a loss of mora sonority.