Lisker L, Rossi M
Department of Linguistics, University of Pennsylvania, Philadelphia 19104.
Lang Speech. 1992 Oct-Dec;35 ( Pt 4):391-417. doi: 10.1177/002383099203500402.
That lipreading plays a role in phoneme recognition, even when the acoustic signal alone is phonologically unambiguous, has been concluded from experiments in the perception of discrepant combinations of acoustic and visual speech signals. Little is known about the effect of visual information on explicitly phonetic judgments, the kind of judgments made by trained observers that are the basis for describing the phonological pattern of a language. In this study some isolated vowels, most of them similar to vowels in standard French, were produced in ten random orders by an experienced phonetician. The acoustic signals and frontal views of the lower half of the speaker's face were recorded on video tape. By computer editing, audiovisual stimuli were prepared in which pairs of vowels supposed to differ primarily in rounding were variously combined. Twenty French-speaking speech researchers carried out three tasks: to decide on the rounding of each vowel by sound alone, by sight alone, and by sound when accompanied by matching or discrepant images of the talker. Their summed responses indicate that, despite the instruction to base decisions on the auditory signal, visual evidence of speech activity significantly "perturbed" subjects' rounding judgments. However, the lipreading effect varied greatly across both subjects and vowels. Most subjects judged most vowels strictly on the basis of the auditory information, while for others lipreading exerted paramount influence. Only a small minority responded so as to indicate any integration of discrepant rounding information registered by ear and eye.
即使仅声学信号在语音学上是明确无误的，唇读在音素识别中也发挥着作用，这是从对声学和视觉语音信号的差异组合的感知实验中得出的结论。关于视觉信息对明确的语音判断的影响，人们知之甚少，这种判断是由经过训练的观察者做出的，是描述一种语言的语音模式的基础。在这项研究中，一位经验丰富的语音学家以十种随机顺序发出了一些孤立的元音，其中大多数类似于标准法语中的元音。声学信号和说话者下半张脸的正视图被录制在录像带上。通过计算机编辑，准备了视听刺激材料，其中主要在圆唇度上有所不同的元音对以各种方式组合在一起。二十位说法语的语音研究人员进行了三项任务：仅通过声音、仅通过视觉以及在伴有说话者匹配或不一致图像的声音的情况下，来确定每个元音的圆唇度。他们的综合反应表明，尽管有基于听觉信号做出判断的指示，但语音活动的视觉证据显著“干扰”了受试者的圆唇度判断。然而，唇读效果在受试者和元音之间差异很大。大多数受试者主要根据听觉信息判断大多数元音，而对另一些人来说，唇读发挥了至关重要的影响。只有一小部分人的反应表明他们整合了耳朵和眼睛接收到的不一致的圆唇度信息。
