Perceptual Fusion Tendency of Speech Sounds
| Autor: | Xihong Wu, Lihua Mao, Xuefei Zou, Jingyu Li, Tianshu Qu, Yanhong Wu, Liang Li, Ying Huang |
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| Rok vydání: | 2011 |
| Předmět: |
Adult
Male Time Factors Cognitive Neuroscience Speech recognition media_common.quotation_subject Statistics as Topic Speech sounds Functional Laterality Young Adult Phonetics Perception Image Processing Computer-Assisted Humans Sound image media_common Motor theory of speech perception Sound (medical instrument) Analysis of Variance Communication Fusion business.industry Brain Auditory Threshold Speech processing Magnetic Resonance Imaging Oxygen Noise Acoustic Stimulation Speech Perception Female business Psychology |
| Zdroj: | Journal of Cognitive Neuroscience. 23:1003-1014 |
| ISSN: | 1530-8898 0898-929X |
| Popis: | To discriminate and to recognize sound sources in a noisy, reverberant environment, listeners need to perceptually integrate the direct wave with the reflections of each sound source. It has been confirmed that perceptual fusion between direct and reflected waves of a speech sound helps listeners recognize this speech sound in a simulated reverberant environment with disrupting sound sources. When the delay between a direct sound wave and its reflected wave is sufficiently short, the two waves are perceptually fused into a single sound image as coming from the source location. Interestingly, compared with nonspeech sounds such as clicks and noise bursts, speech sounds have a much larger perceptual fusion tendency. This study investigated why the fusion tendency for speech sounds is so large. Here we show that when the temporal amplitude fluctuation of speech was artificially time reversed, a large perceptual fusion tendency of speech sounds disappeared, regardless of whether the speech acoustic carrier was in normal or reversed temporal order. Moreover, perceptual fusion of normal-order speech, but not that of time-reversed speech, was accompanied by increased coactivation of the attention-control-related, spatial-processing-related, and speech-processing-related cortical areas. Thus, speech-like acoustic carriers modulated by speech amplitude fluctuation selectively activate a cortical network for top–down modulations of speech processing, leading to an enhancement of perceptual fusion of speech sounds. This mechanism represents a perceptual-grouping strategy for unmasking speech under adverse conditions. |
| Databáze: | OpenAIRE |
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