Ohde R N, Ochs M T
Division of Hearing and Speech Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee 37212, USA.
J Acoust Soc Am. 1996 Oct;100(4 Pt 1):2486-99. doi: 10.1121/1.417357.
It has been hypothesized that the acoustic properties within a temporal domain of 10 to 30 ms of boundaries between speech sounds contain significant information on the phonetic features of segments, and that these cues are perceptually integrated by the auditory system [Stevens, Phonetic Linguistics: Essays in Honor of Peter Ladefoged (Academic, London, 1985)]. The purpose of the current research was to examine the effects of stimulus duration adjacent to speech sound boundaries on the perceptual integration of place of articulation of nasals before and after disruption of the abrupt changes in spectra between the murmur and transition. In experiment I, three children, aged 3, 5, and 7 years, and an adult female and male produced consonant-vowel (CV) syllables consisting of [m] and [n] in four vowel contexts, [i ae u a]. Approximately 25-ms segments of the murmur and vowel transition adjacent to the speech sound boundary were digitally removed from these productions. Intervals of silence ranging from 0 to 2000 ms, which can potentially perturb integration processes, were inserted between these segments. The stimuli were then presented to adult listeners for the identification of the nasal. The main findings revealed a consistent decline in identification with gap durations up to 150 ms across speakers and vowel context. However, the adult labial feature was resistant to perceptual change as a function of gap duration. This result appeared to relate to formant transition duration, and not to response bias. In experiment II, stimuli with durations shorter than those in experiment I were further analyzed for adult speakers. The main finding was a quantification of the acoustic segment duration needed for perceptual integration of the murmur and vowel transition. Across both experiments, the results reveal a decline in the identification of both alveolar and labial nasals within a time interval mediated by short-term auditory memory, and that the duration of the acoustic segment needed for perceptual integration is longer for [n] than [m].
据推测，语音之间10至30毫秒时间域内的声学特性包含有关音段语音特征的重要信息，并且这些线索由听觉系统进行感知整合[史蒂文斯，《语音语言学：纪念彼得·拉德福格德的论文集》（学术出版社，伦敦，1985年）]。当前研究的目的是在鼻音和过渡音之间频谱的突然变化被破坏之前和之后，研究与语音边界相邻的刺激持续时间对鼻音发音部位感知整合的影响。在实验I中，三名儿童（年龄分别为3岁、5岁和7岁）以及一名成年女性和一名成年男性在四种元音环境[i、æ、u、a]中发出由[m]和[n]组成的辅音-元音（CV）音节。从这些发音中以数字方式去除与语音边界相邻的大约25毫秒的鼻音和元音过渡音段。在这些音段之间插入0至2000毫秒不等的静音间隔，这可能会干扰整合过程。然后将这些刺激呈现给成年听众以识别鼻音。主要研究结果表明，在不同说话者和元音环境中，随着间隔持续时间增加到150毫秒，识别率持续下降。然而，成年唇音特征对感知变化具有抗干扰能力，不受间隔持续时间的影响。这一结果似乎与共振峰过渡持续时间有关，而与反应偏差无关。在实验II中，对成年说话者的持续时间比实验I中更短的刺激进行了进一步分析。主要研究结果是对鼻音和元音过渡音感知整合所需的声学音段持续时间进行了量化。在两个实验中，结果都表明在由短期听觉记忆介导的时间间隔内，齿龈鼻音和唇鼻音的识别率都会下降；并且感知整合所需的声学音段持续时间对于[n]比对于[m]更长。
