Heald Shannon L M, Van Hedger Stephen C, Nusbaum Howard C
Department of Psychology, The University of Chicago, ChicagoIL, United States.
Front Psychol. 2017 May 23;8:781. doi: 10.3389/fpsyg.2017.00781. eCollection 2017.
In our auditory environment, we rarely experience the exact acoustic waveform twice. This is especially true for communicative signals that have meaning for listeners. In speech and music, the acoustic signal changes as a function of the talker (or instrument), speaking (or playing) rate, and room acoustics, to name a few factors. Yet, despite this acoustic variability, we are able to recognize a sentence or melody as the same across various kinds of acoustic inputs and determine meaning based on listening goals, expectations, context, and experience. The recognition process relates acoustic signals to prior experience despite variability in signal-relevant and signal-irrelevant acoustic properties, some of which could be considered as "noise" in service of a recognition goal. However, some acoustic variability, if systematic, is lawful and can be exploited by listeners to aid in recognition. Perceivable changes in systematic variability can herald a need for listeners to reorganize perception and reorient their attention to more immediately signal-relevant cues. This view is not incorporated currently in many extant theories of auditory perception, which traditionally reduce psychological or neural representations of perceptual objects and the processes that act on them to static entities. While this reduction is likely done for the sake of empirical tractability, such a reduction may seriously distort the perceptual process to be modeled. We argue that perceptual representations, as well as the processes underlying perception, are dynamically determined by an interaction between the uncertainty of the auditory signal and constraints of context. This suggests that the process of auditory recognition is highly context-dependent in that the identity of a given auditory object may be intrinsically tied to its preceding context. To argue for the flexible neural and psychological updating of sound-to-meaning mappings across speech and music, we draw upon examples of perceptual categories that are thought to be highly stable. This framework suggests that the process of auditory recognition cannot be divorced from the short-term context in which an auditory object is presented. Implications for auditory category acquisition and extant models of auditory perception, both cognitive and neural, are discussed.
在我们的听觉环境中，我们很少会两次经历完全相同的声学波形。对于对听众有意义的交际信号来说尤其如此。在语音和音乐中，声学信号会根据说话者（或乐器）、说话（或演奏）速度以及房间声学等因素而变化，仅举这几个因素为例。然而，尽管存在这种声学变异性，我们仍能够在各种声学输入中识别出同一句话或旋律，并根据听力目标、期望、语境和经验来确定其含义。识别过程将声学信号与先前的经验联系起来，尽管信号相关和信号无关的声学特性存在变异性，其中一些特性在识别目标的服务中可能被视为“噪声”。然而，一些声学变异性，如果是系统性的，则是有规律的，听众可以利用它来辅助识别。系统性变异性中可感知的变化可能预示着听众需要重新组织感知并将注意力重新导向更直接与信号相关的线索。目前，许多现存的听觉感知理论并未纳入这一观点，这些理论传统上会将感知对象的心理或神经表征以及作用于它们的过程简化为静态实体。虽然这种简化可能是为了便于进行实证研究，但这种简化可能会严重扭曲要建模的感知过程。我们认为，感知表征以及感知背后的过程是由听觉信号的不确定性与语境约束之间的相互作用动态决定的。这表明听觉识别过程高度依赖语境，因为给定听觉对象的身份可能本质上与其先前的语境相关联。为了论证跨语音和音乐的声音到意义映射的灵活神经和心理更新，我们借鉴了被认为高度稳定的感知类别的例子。这个框架表明，听觉识别过程不能与呈现听觉对象的短期语境分开。文中还讨论了对听觉类别习得以及现存的认知和神经听觉感知模型的影响。
