苗栗四縣客家話單字調LZ值轉換聲學分析

Acoustic Analysis of the Citation Tones in Miaoli Sixian Hakka: Based on LZ-value Transformation Formula

本研究利用聲學分析苗栗四縣客家話六個單字調，參與者為12名以苗栗四縣客家話為母語的中年層發音人（男女各半）。本研究首先採集這些發音人的單字調，接著利用PRAAT測量基頻長度，並在基頻曲線上平均選取11個點測量基頻數值，隨後將基頻數值轉換為LZ值。結果顯示，經LZ值公式轉換的六個單字調的調值分別為[34, 31, 41, 55, 42, 55]，這個結果與運用T值公式轉換的結果差異不大。本研究發現，不論是利用T值或LZ值，傳統調查與聲學分析不一致之處均是低調域的單字調。這種情況導因於五度標調法的運用定義不清，以及調值描寫主觀性的問題。據此，未來研究重點應放在如何在五度標調法的框架下進行調值調整，使得低調域單字調在傳統調查與聲學分析之間能趨於一致。

This study acoustically explored six citation tones in Miaoli Sixian Hakka (MSH) in Taiwan by means of LZ-value transformation formula. Twelve middle-aged MSH native speakers participated in this study. This study first recorded their citation tones, and used PRAAT to measure F0duration. The F0 duration was averagely divided into ten portions, and the F0val-ues of the eleven points were extracted out. The fetched F0values were then transformed into LZ values. Analytical results showed that, under LZ-value transformation formula, the tonal values of the six citation tones in MSH were [34, 31, 41, 55, 42, 55] respectively, similar to those under T-value transformation formula. This study found that the descriptive discrepancy between traditional survey and acoustic analysis exists in the citation tones in the low tonal register. This phenomenon results from the unclear definition of how to use the five-point scale and the subjectivity of tonal description. For this sake, future studies should center on how to modulate tonal values under the five-point scale in order to match acoustic analysis with traditional survey.