Acoustic cues underlying auditory distance in barn owls
Acoustic cues underlying auditory distance in barn owls
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DOI：
10.1080/00016480701840114
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发表时间：
2008-01-01
影响因子：
1.4
通讯作者：
Gull, Justin
中科院分区：
文献类型：
--
作者：
Kim, Duck O.;Moiseff, Andrew;Gull, Justin
结论。研究结果表明：(1)在多种线索中，同侧耳内直接与混响（D/R）比的单耳线索提供的声源距离信息最多；(2)声源间声级差（ILD）反映声源距离的信息较少；(3)一个全面的三维听觉定位理论必须包含所有主要的声音线索随距离变化的事实。目标。听觉距离定位的神经机制尚不清楚。目前的研究是填补这一知识空白的第一步。材料和方法。对成年仓鸮的双耳房间脉冲反应进行了测量。声源被放置在相对于猫头鹰头部的不同距离（最高80厘米）和方位角（0-90）上，海拔保持在0。结果。我们确定了3-10 kHz波段的每个线索的值，发现：(1)信号幅度的D/R比提供了有关声源距离的最多信息；(2)同侧D/R比对侧或双侧平均D/R比更清楚地表征距离；(3)在一定条件下，直接信号的ILD随距离的减小而增大；(3)在90方位角处，直接信号的间时差（ITD）随距离的减小而增大；(4) ILD和单耳直接信号的频谱模式随距离变化复杂。
Conclusions. We conclude that: (1) among several cues examined, the monaural cue of direct-to-reverberant (D/R) ratio in the ipsilateral ear provides the most information about sound-source distance; (2) interaural level difference (ILD) provides less information about sound-source distance; and (3) a comprehensive theory of three-dimensional auditory localization must incorporate the fact that all of the major acoustic cues change with distance. Objective. Neural mechanisms underlying auditory localization of distance are poorly understood. The present study was an initial step toward filling this gap in knowledge. Materials and methods. The binaural room impulse responses of adult barn owls were measured. The sound source was placed at various distances (up to 80 cm) and azimuths (0-90) relative to the owl's head, with the elevation kept at 0. Results. We determined the value of each cue for a 3-10 kHz band, and found that: (1) D/R ratio of signal amplitudes provided the most information about sound-source distance; (2) the ipsilateral D/R ratio represented distance more clearly than the contralateral or binaural-average D/R ratios; (3) ILD of direct signals increased with decreasing distance under certain conditions; (3) interaural time difference (ITD) of direct signals increased with decreasing distance at 90 azimuth; and (4) the spectral patterns of ILD and the monaural direct signals changed with distance in complex ways.