Kain Alexander, Amano-Kusumoto Akiko, Hosom John-Paul
Center for Spoken Language Understanding at the OGI School of Science and Engineering, Oregon Health and Science University, 20000 NW Walker Road, Beaverton, Oregon 97006, USA.
J Acoust Soc Am. 2008 Oct;124(4):2308-19. doi: 10.1121/1.2967844.
Speakers naturally adopt a special "clear" (CLR) speaking style in order to be better understood by listeners who are moderately impaired in their ability to understand speech due to a hearing impairment, the presence of background noise, or both. In contrast, speech intended for nonimpaired listeners in quiet environments is referred to as "conversational" (CNV). Studies have shown that the intelligibility of CLR speech is usually higher than that of CNV speech in adverse circumstances. It is not known which individual acoustic features or combinations of features cause the higher intelligibility of CLR speech. The objective of this study is to determine the contribution of some acoustic features to intelligibility for a single speaker. The proposed method creates "hybrid" (HYB) speech stimuli that selectively combine acoustic features of one sentence spoken in the CNV and CLR styles. The intelligibility of these stimuli is then measured in perceptual tests, using 96 phonetically balanced sentences. Results for one speaker show significant sentence-level intelligibility improvements over CNV speech when replacing certain combinations of short-term spectra, phoneme identities, and phoneme durations of CNV speech with those from CLR speech, but no improvements for combinations involving fundamental frequency, energy, or nonspeech events (pauses).
由于听力障碍、存在背景噪音或两者皆有，听众理解言语的能力受到一定程度损害，为了让这些听众能更好地理解，说话者自然会采用一种特殊的“清晰”（CLR）说话方式。相比之下，在安静环境中面向听力正常听众的言语被称为“会话式”（CNV）。研究表明，在不利环境下，CLR言语的可懂度通常高于CNV言语。目前尚不清楚是哪些个体声学特征或特征组合导致了CLR言语具有更高的可懂度。本研究的目的是确定某些声学特征对单个说话者可懂度的贡献。所提出的方法创建了“混合”（HYB）言语刺激，其选择性地组合了以CNV和CLR方式说出的一个句子的声学特征。然后，使用96个语音平衡的句子，在感知测试中测量这些刺激的可懂度。一位说话者的结果显示，用CLR言语的某些短期频谱、音素识别和音素时长组合替换CNV言语的这些组合时，句子层面的可懂度比CNV言语有显著提高，但涉及基频、能量或非言语事件（停顿）的组合则没有提高。
