Neutralization of Short Tones in Taiwanese

This paper is an acoustic study of neutralization of short tones in Taiwanese. The results show that the two short tones were completely neutralized in juncture position. Since long tones in Taiwanese show complete neutralization in context position, the bidirectionality of tone alternation in Taiwanese Tone Sandhi poses a problem far rule-based approaches, while it is consistent with the hypothesis that both juncture and context tones are listed in the lexicon, instead of one being derived from the other. Moreover, in order to account for the difference between Taiwanese Tone Sandhi and Mandarin Tone Sandhi (which has been proven acoustically to be incomplete neutralization), the Naturalness Hypothesis is proposed, which claims that if the neutralization is phonetically unnatural, then the neutralization is more likely to be lexicalized and show complete neutralization.