David Marion, Lavandier Mathieu, Grimault Nicolas, Oxenham Andrew J
Department of Psychology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Univ Lyon, ENTPE, Laboratoire Génie Civil et bâtiment, Rue Maurice Audin, 69518 Vaulx-en-Velin Cedex, France.
J Acoust Soc Am. 2017 Sep;142(3):1674. doi: 10.1121/1.5003809.
Differences in spatial cues, including interaural time differences (ITDs), interaural level differences (ILDs) and spectral cues, can lead to stream segregation of alternating noise bursts. It is unknown how effective such cues are for streaming sounds with realistic spectro-temporal variations. In particular, it is not known whether the high-frequency spectral cues associated with elevation remain sufficiently robust under such conditions. To answer these questions, sequences of consonant-vowel tokens were generated and filtered by non-individualized head-related transfer functions to simulate the cues associated with different positions in the horizontal and median planes. A discrimination task showed that listeners could discriminate changes in interaural cues both when the stimulus remained constant and when it varied between presentations. However, discrimination of changes in spectral cues was much poorer in the presence of stimulus variability. A streaming task, based on the detection of repeated syllables in the presence of interfering syllables, revealed that listeners can use both interaural and spectral cues to segregate alternating syllable sequences, despite the large spectro-temporal differences between stimuli. However, only the full complement of spatial cues (ILDs, ITDs, and spectral cues) resulted in obligatory streaming in a task that encouraged listeners to integrate the tokens into a single stream.
包括双耳时间差（ITD）、双耳声级差（ILD）和频谱线索在内的空间线索差异，可能导致交替噪声脉冲串的流分离。目前尚不清楚这些线索对于具有现实频谱-时间变化的声音流分离有多有效。特别是，尚不清楚与仰角相关的高频频谱线索在这种情况下是否仍足够稳健。为了回答这些问题，生成了辅音-元音音素序列，并通过非个性化的头部相关传递函数进行滤波，以模拟与水平和中平面中不同位置相关的线索。一项辨别任务表明，当刺激保持恒定时以及在不同呈现之间变化时，听众都能够辨别双耳线索的变化。然而，在存在刺激变异性的情况下，对频谱线索变化的辨别要差得多。一项基于在干扰音节存在的情况下检测重复音节的流分离任务表明，尽管刺激之间存在很大的频谱-时间差异，但听众可以使用双耳线索和频谱线索来分离交替的音节序列。然而，只有完整的空间线索（ILD、ITD和频谱线索）在一项鼓励听众将音素整合为单个流的任务中导致了强制性流分离。
