Clarke Jeanne, Gaudrain Etienne, Chatterjee Monita, Başkent Deniz
University of Groningen, University Medical Center Groningen, Department of Otorhinolaryngology/Head and Neck Surgery, Groningen, The Netherlands; University of Groningen, Graduate School of Medical Sciences, Research School of Behavioral and Cognitive Neurosciences, Groningen, The Netherlands.
Boys Town National Research Hospital, Omaha, NE 68131, USA.
Hear Res. 2014 Sep;315:80-7. doi: 10.1016/j.heares.2014.07.002. Epub 2014 Jul 11.
Phonemic restoration, or top-down repair of speech, is the ability of the brain to perceptually reconstruct missing speech sounds, using remaining speech features, linguistic knowledge and context. This usually occurs in conditions where the interrupted speech is perceived as continuous. The main goal of this study was to investigate whether voice continuity was necessary for phonemic restoration. Restoration benefit was measured by the improvement in intelligibility of meaningful sentences interrupted with periodic silent gaps, after the gaps were filled with noise bursts. A discontinuity was induced on the voice characteristics. The fundamental frequency, the vocal tract length, or both of the original vocal characteristics were changed using STRAIGHT to make a talker sound like a different talker from one speech segment to another. Voice discontinuity reduced the global intelligibility of interrupted sentences, confirming the importance of vocal cues for perceptually constructing a speech stream. However, phonemic restoration benefit persisted through all conditions despite the weaker voice continuity. This finding suggests that participants may have relied more on other cues, such as pitch contours or perhaps even linguistic context, when the vocal continuity was disrupted.
音素恢复,即言语的自上而下修复,是大脑利用剩余语音特征、语言知识和语境在感知层面重建缺失语音的能力。这通常发生在被打断的言语被感知为连续的情况下。本研究的主要目的是调查语音连续性对于音素恢复是否必要。通过用噪声脉冲填充周期性静音间隙后,被打断的有意义句子的可懂度提高情况来衡量恢复效益。在语音特征上引入了不连续性。使用STRAIGHT改变原始语音特征的基频、声道长度或两者,使说话者在不同语音片段听起来像不同的人。语音不连续性降低了被打断句子的整体可懂度,证实了语音线索对于在感知层面构建语音流的重要性。然而,尽管语音连续性较弱,音素恢复效益在所有条件下都持续存在。这一发现表明,当语音连续性被破坏时,参与者可能更多地依赖其他线索,如音高轮廓甚至可能是语言语境。