Clifton Rachel K, Freyman Richard L, Meo Jennifer
Department of Psychology, University of Massachusetts, Amherst 01003, USA.
Percept Psychophys. 2002 Feb;64(2):180-8. doi: 10.3758/bf03195784.
Sound produced in a room is typically followed by numerous reflected sounds from nearby surfaces; yet we perceive a single sound source. This perceptual phenomenon, known as the precedence effect, has long been assumed to involve echo suppression, but the nature of this suppression remains unclear. In two experiments, we investigated whether information about the lagging sound's location was perceived. Our hypothesis was that such information is critical because reflected sound can function to inform the listener about objects and structures in the room. Listeners reported hearing more echoes under a stimulus situation that simulated sudden, unexpected changes in the location of the lagging sounds, as compared with stable stimulus conditions. Placement of lagging sounds' locations proved to be critical in that a sudden shift per se did not disrupt the fusion aspect of the precedence effect; the new location had to occupy a site that specified a new reflecting surface. Perception of echoes appears to be modulated by room acoustic information contained in reflected sound and listeners' expectations about this.
房间中产生的声音通常会伴随着来自附近表面的大量反射声；然而我们却感知到一个单一的声源。这种被称为优先效应的感知现象长期以来一直被认为涉及回声抑制，但其抑制的本质仍不清楚。在两个实验中，我们研究了关于滞后声音位置的信息是否能被感知。我们的假设是，此类信息至关重要，因为反射声可以起到向听众告知房间内物体和结构的作用。与稳定的刺激条件相比，在模拟滞后声音位置突然、意外变化的刺激情境下，听众报告听到了更多回声。滞后声音位置的放置被证明是关键的，因为位置的突然改变本身并不会破坏优先效应的融合方面；新位置必须占据一个指定新反射面的位置。回声的感知似乎受到反射声中包含的房间声学信息以及听众对此的期望的调节。
