Larsen Erik, Iyer Nandini, Lansing Charissa R, Feng Albert S
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
J Acoust Soc Am. 2008 Jul;124(1):450-61. doi: 10.1121/1.2936368.
The goals of this study were to measure sensitivity to the direct-to-reverberant energy ratio (D/R) across a wide range of D/R values and to gain insight into which cues are used in the discrimination process. The main finding is that changes in D/R are discriminated primarily based on spectral cues. Temporal cues may be used but only when spectral cues are diminished or not available, while sensitivity to interaural cross-correlation is too low to be useful in any of the conditions tested. These findings are based on an acoustic analysis of these variables and the results of two psychophysical experiments. The first experiment employs wideband noise with two values for onset and offset times to determine the D/R just-noticeable difference at -10, 0, 10, and 20 dB D/R. This yielded substantially higher sensitivity to D/R at 0 and 10 dB D/R (2-3 dB) than has been reported previously, while sensitivity is much lower at -10 and 20 dB D/R. The second experiment consists of three parts where specific cues to D/R are reduced or removed, which enabled the specified rank ordering of the cues. The acoustic analysis and psychophysical experiments also provide an explanation for the "auditory horizon effect."
本研究的目标是测量在广泛的直达声与混响声能量比（D/R）值范围内对其的敏感度，并深入了解在辨别过程中使用了哪些线索。主要发现是，D/R的变化主要基于频谱线索进行辨别。时间线索可能会被使用，但仅在频谱线索减弱或不可用时，而双耳互相关的敏感度太低，在任何测试条件下都无用。这些发现基于对这些变量的声学分析以及两个心理物理学实验的结果。第一个实验采用具有两种起始和结束时间值的宽带噪声，以确定在-10、0、10和20 dB D/R时的D/R刚可察觉差异。这在0和10 dB D/R（2 - 3 dB）时对D/R的敏感度比之前报道的要高得多，而在-10和20 dB D/R时敏感度则低得多。第二个实验由三个部分组成，其中对D/R的特定线索被减少或去除，这使得能够对线索进行指定的排序。声学分析和心理物理学实验也为“听觉地平线效应”提供了解释。
