Department of Linguistics, University of Arizona, Box 210028, Tucson, Arizona 85721-0028, USA.
J Acoust Soc Am. 2011 Sep;130(3):1606-17. doi: 10.1121/1.3621306.
Variability is perhaps the most notable characteristic of speech, and it is particularly noticeable in spontaneous conversational speech. The current research examines how speakers realize the American English stops /p, k, b, g/ and flaps (ɾ from /t, d/), in casual conversation and in careful speech. Target consonants appear after stressed syllables (e.g., "lobby") or between unstressed syllables (e.g., "humanity"), in one of six segmental/word-boundary environments. This work documents the degree and types of variability listeners encounter and must parse. Findings show greater reduction in connected and spontaneous speech, greater reduction in high frequency phrases (but not within high frequency words), and greater reduction between unstressed syllables than after a stress. Although highly reduced productions of stops and flaps occur often, with approximant-like tokens even in careful speech, reduction does not lead to a large amount of overlap between phonological categories. Approximant-like realizations of expected stops and flaps in some conditions constitute the majority of tokens. This shows that reduced speech is something that listeners encounter, and must perceive, in a large proportion of the speech they hear.
变异性或许是言语最显著的特征，而在自然的会话言语中尤为明显。本研究考察了说话者在日常会话和刻意说话中，如何实现英语的清爆破音 /p, k, b, g/ 和闪音 (ɾ 来自 /t, d/)。目标辅音出现在重读音节（如“lobby”）之后或非重读音节之间（如“humanity”），有六种音段/词界环境。本研究记录了说话者遇到的并需要进行切分的变异性的程度和类型。研究结果表明，在连贯和自然的言语中，爆破音和闪音的弱化程度更大，高频词（而非高频短语）中的弱化程度更大，而非重读音节之间的弱化程度大于重读音节后的弱化程度。尽管在刻意说话中，即使是在接近音的音位上，也常出现高度弱化的塞音和闪音，但弱化并不会导致音位类别的大量重叠。在某些条件下，预期的塞音和闪音的近似音位实现构成了大多数的音位。这表明，在他们听到的大部分言语中，说话者会遇到并需要感知到弱化的言语。
