Uchanski R M, Choi S S, Braida L D, Reed C M, Durlach N I
Massachusetts Institute of Technology, Cambridge, USA.
J Speech Hear Res. 1996 Jun;39(3):494-509. doi: 10.1044/jshr.3903.494.
The contribution of reduced speaking rate to the intelligibility of "clear" speech (Picheny, Durlach, & Braida, 1985) was evaluated by adjusting the durations of speech segments (a) via nonuniform signal time-scaling, (b) by deleting and inserting pauses, and (c) by eliciting materials from a professional speaker at a wide range of speaking rates. Key words in clearly spoken nonsense sentences were substantially more intelligible than those spoken conversationally (15 points) when presented in quiet for listeners with sensorineural impairments and when presented in a noise background to listeners with normal hearing. Repeated presentation of conversational materials also improved scores (6 points). However, degradations introduced by segment-by-segment time-scaling rendered this time-scaling technique problematic as a means of converting speaking styles. Scores for key words excised from these materials and presented in isolation generally exhibited the same trends as in sentence contexts. Manipulation of pause structure reduced scores both when additional pauses were introduced into conversational sentences and when pauses were deleted from clear sentences. Key-word scores for materials produced by a professional talker were inversely correlated with speaking rate, but conversational rate scores did not approach those of clear speech for other talkers. In all experiments, listeners with normal hearing exposed to flat-spectrum background noise performed similarly to listeners with hearing loss.
通过以下方式调整语音片段的时长，评估了降低语速对“清晰”语音可懂度的贡献（Picheny、Durlach和Braida，1985）：（a）通过非均匀信号时间缩放；（b）通过删除和插入停顿；（c）通过让专业演讲者以广泛的语速生成材料。对于感音神经性损伤的听众，在安静环境中呈现时，清晰说出的无意义句子中的关键词比对话式说出的关键词更易理解（高15分）；对于听力正常的听众，在噪声背景中呈现时也是如此。重复呈现对话材料也提高了分数（6分）。然而，逐段时间缩放引入的退化使得这种时间缩放技术作为转换说话风格的手段存在问题。从这些材料中提取并单独呈现的关键词分数总体上呈现出与句子语境中相同的趋势。当在对话句子中引入额外停顿以及从清晰句子中删除停顿时，停顿结构的操纵都会降低分数。专业演讲者生成的材料的关键词分数与语速呈负相关，但其他演讲者的对话语速分数并未接近清晰语音的分数。在所有实验中，暴露于平坦频谱背景噪声的听力正常的听众与听力损失的听众表现相似。
