Spatial Hearing Lab, College of Health Solutions, Arizona State University, Tempe, Arizona 85004, USA.
J Acoust Soc Am. 2023 Aug 1;154(2):661-670. doi: 10.1121/10.0020563.
Front-back reversals (FBRs) in sound-source localization tasks due to cone-of-confusion errors on the azimuth plane occur with some regularity, and their occurrence is listener-dependent. There are fewer FBRs for wideband, high-frequency sounds than for low-frequency sounds presumably because the sources of low-frequency sounds are localized on the basis of interaural differences (interaural time and level differences), which can lead to ambiguous responses. Spectral cues can aid in determining sound-source locations for wideband, high-frequency sounds, and such spectral cues do not lead to ambiguous responses. However, to what extent spectral features might aid sound-source localization is still not known. This paper explores conditions in which the spectral profile of two-octave wide noise bands, whose sources were localized on the azimuth plane, were randomly varied. The experiment demonstrated that such spectral profile randomization increased FBRs for high-frequency noise bands, presumably because whatever spectral features are used for sound-source localization were no longer as useful for resolving FBRs, and listeners relied on interaural differences for sound-source localization, which led to response ambiguities. Additionally, head rotation decreased FBRs in all cases, even when FBRs increased due to spectral profile randomization. In all cases, the occurrence of FBRs was listener-dependent.
在声源定位任务中，由于在方位平面上的混响误差，会出现前后反转（FBR），并且其出现与听者有关。与低频声音相比，宽带高频声音的 FBR 较少，这可能是因为低频声音的声源是基于耳间差异（耳间时间和水平差异）进行定位的，这可能导致模糊的反应。频谱线索可以帮助确定宽带高频声音的声源位置，而这种频谱线索不会导致模糊的反应。然而，到目前为止，还不清楚频谱特征在多大程度上可以帮助声源定位。本文探讨了在随机改变其声源位于方位平面上的两个八度宽噪声带的频谱轮廓的条件下，这种随机变化会增加高频噪声带的 FBR。实验表明，这种频谱轮廓随机化增加了高频噪声带的 FBR，可能是因为用于声源定位的任何频谱特征不再像以前那样有助于解决 FBR，而听者依赖于耳间差异进行声源定位，这导致了反应的模糊性。此外，即使由于频谱轮廓随机化导致 FBR 增加，头部旋转也会降低所有情况下的 FBR。在所有情况下，FBR 的出现都与听者有关。
