Remez Robert E, Thomas Emily F, Wycoff Andrea M, Giglio Rebecca E, Crank Aislinn T, Cheimets Chloe B, Koinis Stavroula M
a Department of Psychology and Program in Neuroscience & Behavior , Barnard College, Columbia University , New York , New York , USA.
Exp Aging Res. 2016;42(1):3-13. doi: 10.1080/0361073X.2016.1108741.
BACKGROUND/STUDY CONTEXT: The perception of speech requires the integration of sensory details from a rapidly fading trace of a time-varying spectrum. This effortful cognitive function has been difficult to assess. New tests measuring intelligibility of sine-wave replicas of speech provided an assay of this critical function in normal-hearing young adults.
Four time-varying sinusoids replicated the frequency and amplitude variation of the natural resonances of spoken sentences. The temporal tolerance of perceptual integration of speech was measured by determining the effect on intelligibility of desynchronizing a single sine-wave component in each sentence. This method was applied in tests in which the sentences were temporally compressed or expanded over a 40% range.
Desynchrony was harmful to perceptual integration over a narrow temporal range, indicating that modulation sensitivity is keyed to a rate of 20 Hz. No effect of variation in speech rate was observed on the intelligibility measure, whether rate was accelerated or decelerated relative to the natural rate.
Performance measures of desynchrony tolerance did not vary when speech rate was accelerated or decelerated, revealing constraints on integration that are arguably primitive, sensory, auditory, and fixed. Because these are not adaptable, they limit the potential for perceptual learning in this aspect of perceptual organization. Implications for describing the elderly listener are noted.
背景/研究背景：言语感知需要整合来自时变频谱快速衰减痕迹的感官细节。这项费力的认知功能一直难以评估。新的测量言语正弦波复制品可懂度的测试为正常听力的年轻人的这一关键功能提供了一种检测方法。
四个时变正弦波复制了口语句子自然共振的频率和幅度变化。通过确定使每个句子中的单个正弦波分量不同步对可懂度的影响来测量言语感知整合的时间耐受性。该方法应用于句子在40%范围内进行时间压缩或扩展的测试中。
在狭窄的时间范围内，不同步对感知整合有害，表明调制敏感性以20赫兹的速率为关键。无论语速相对于自然语速是加快还是减慢，在可懂度测量中均未观察到语速变化的影响。
当语速加快或减慢时，不同步耐受性的性能测量没有变化，揭示了整合方面可说是原始的、感官的、听觉的和固定的限制。由于这些是不可适应的，它们限制了在感知组织的这一方面进行感知学习的潜力。文中指出了对描述老年听众的影响。
