Max Planck Institute for Psycholinguistics, P.O. Box 310, 6500 AH, Nijmegen, The Netherlands.
J Acoust Soc Am. 2019 Jul;146(1):179. doi: 10.1121/1.5116004.
Speech can be produced at different rates. Listeners take this rate variation into account by normalizing vowel duration for contextual speech rate: An ambiguous Dutch word /m?t/ is perceived as short /mɑt/ when embedded in a slow context, but long /ma:t/ in a fast context. While some have argued that this rate normalization involves low-level automatic perceptual processing, there is also evidence that it arises at higher-level cognitive processing stages, such as decision making. Prior research on rate-dependent speech perception has only used explicit recognition tasks to investigate the phenomenon, involving both perceptual processing and decision making. This study tested whether speech rate normalization can be observed without explicit decision making, using a cross-modal repetition priming paradigm. Results show that a fast precursor sentence makes an embedded ambiguous prime (/m?t/) sound (implicitly) more /a:/-like, facilitating lexical access to the long target word "maat" in a (explicit) lexical decision task. This result suggests that rate normalization is automatic, taking place even in the absence of an explicit recognition task. Thus, rate normalization is placed within the realm of everyday spoken conversation, where explicit categorization of ambiguous sounds is rare.
语速可以有所不同。听众会根据语境语速将元音时长标准化，从而将语速的这种变化考虑在内：一个有歧义的荷兰语单词 /m?t/，如果嵌入到一个较慢的语境中，就会被感知为短音 /mɑt/，但如果嵌入到一个较快的语境中，就会被感知为长音 /ma:t/。虽然有人认为这种语速归一化涉及到低水平的自动感知处理，但也有证据表明它出现在更高水平的认知处理阶段，如决策。先前关于语速依赖的语音感知的研究仅使用显式识别任务来研究这一现象，涉及感知处理和决策。本研究使用跨模态重复启动范式测试了在没有显式决策的情况下是否可以观察到语速归一化。结果表明，一个快速的前导句使嵌入的模糊的前导词 (/m?t/) 听起来（隐含地）更像 /a:/- ，从而促进了在（显式）词汇判断任务中对长目标词“maat”的词汇访问。这一结果表明，语速归一化是自动的，即使在没有显式识别任务的情况下也是如此。因此，语速归一化被置于日常口语对话的范围内，在这种情况下，对有歧义的声音进行显式分类是罕见的。
