Abstract:   The research aims to make comparative analysis of the acoustic features of the stops in lettered-words and Chinese Mandarin, so as to discover if Chinese Mandarin stop system has been changed by the widely-used letteredwords.VOT (Voice Onset Time) and GAP (or Closure) are measured for the two groups of samples, the stops in lettered-words and the stops in two-character Chinese phrases. Analyzing the VOT of the samples, the research finds that, in lettered-words pronunciation, there is no voiced stop at all, and the original voiced stops in English have changed into unaspirated voiceless stops. Statistic analysis shows that there is no significant difference between the VOT of the stops in lettered-words and those in Chinese phrases. Moreover, the acoustic pattern figures of the stops are constructed, based on the averages of VOT and GAP. The figures show that the stops in the two groups of samples have the same acoustic patterns, which further proves that they are of the same class of sound. The result reveals that both the stops in lettered-words and those in Chinese Mandarin are voiceless stops with the distinctive feature of being aspirated or unaspirated. Though widely used for decades, lettered-words haven’t brought voiced stops from English into Chinese Mandarin, which keeps the important distinctive feature [±aspirated], so the stop system in Chinese Mandarin has not changed.

Keywords: lettered-word; Chinese Mandarin; stop; VOT; GAP; acoustic feature

摘要：   本研究采用实验的方法，对比分析了字母词塞音和普通话塞音两种样本的VOT 并进行统计检验，发现字母词中英语本身的浊塞音变为不送气清塞音，具有普通话塞音的声学特征，同时两种样本的VOT 无显著差异。由GAP 和VOT 平均值构建出塞音格局图，显示两种样本声学格局一致，属同一类音。字母词塞音和普通话塞音一样，是清塞音，通过送气与否形成对立；字母词并未将浊塞音引入普通话，普通话塞音仍保留了送气这一重要区别特征，其塞音体系没有改变。

关键词: 字母词, 普通话, 塞音, VOT, GAP, 声学特征