台灣華語自然語料中無聲捲舌音及齒音之聲學研究

Abstract

本研究旨在探討無聲捲舌音及齒音在台灣華語中的表現。過去的研究可以概括分為兩大類：以自然語料所做的社會語言學研究以及運用實驗材料所進行的聲學測量。由於研究材料和方法的限制，先前並未有從聲學角度探討自然語料的研究。有鑑於此，本研究以自然語料為研究材料，並且以聲學測量為研究方式來分析無聲捲舌音及齒音在台灣華語中的呈現。本研究共有十五位男女發音人，皆出生於台北或高雄。每位發音人參與約三十分鐘的訪談。在訪談語料中，所有的無聲捲舌音及齒音皆挑選出來並進行量測。本研究所採用的聲學測量是取頻譜的重心頻率值，且一併分析了四個因素，包括兩個社會因素：地區和性別，及兩個語言因素：重音程度及詞類。研究結果顯示，地區和性別皆有顯著影響。就性別因素而言，女生對於捲舌音和齒音的區分較為男生明顯。而就地區因素而言，男女生呈現不同的趨勢：台北女生的區分程度比高雄女生大，然而台北男生的區分程度卻比高雄男生小。至於兩個語言因素，結果亦發現兩者皆有顯著影響。在重音的情況下，捲舌音和齒音的區分程度較大；而相似的結果也出現在實詞的情況下。再者，研究結果顯示捲舌音化與齒音化這兩個音韻過程在台灣華語有著不同的功能。捲舌音化與社會因素(性別和地區)息息相關，而齒音化卻是與語言因素(重音程度和詞類)有相互關聯。進一步詮釋，本研究發現在台灣華語中，捲舌音化是呈現外在語言因素的不同；反之，齒音化能呈現語言內部的分類及差異。

The present study investigated the realizations of voiceless retroflex and dental sibilants in Taiwan Mandarin. Past studies on this issue are mainly of two tracks – sociolinguistic studies on spontaneous speech and acoustic studies on experimental data. In this study we would like to examine sibilant realizations in spontaneous speech from the acoustic perspective. Fifteen speakers of both genders from two regions, Taipei and Kaohsiung, were recruited and each speaker contributed 30-minute-long speech data. All retroflex and dental sibilant tokens were labeled, and the centroid frequency of each sibilant was measured to determine its realization. Effects of four factors were looked into, including two social factors, region and gender, and two linguistic factors, prosodic prominence and word class. Results showed that both region and gender played determinant roles. Females generally made larger sibilant contrasts than males, but inconsistency was observed for cross-regional comparisons. While Taipei females distinguished sibilants better than Kaohsiung females, the opposite was observed for male speakers. As for the effects of linguistic factors, it was also found that sibilant realizations in Taiwan Mandarin were indeed subject to both prosodic prominence and word class. In particular, the strengthening effect was shown in linguistically prominent conditions – prosodically prominent and content word conditions, in which speakers tended to make greater sibilant distinctions. Our results further implicated distinctive functions for the processes of retroflexion and dentalization in Taiwan Mandarin. Retroflexion characterized speaker group discrepancies, while dentalization reflected different levels of linguistic prominence. In this regard, degrees of retroflexion were sensitive to extra-linguistic differences, whereas degrees of dentalization were sensitive to language-internal categorization.