Simmons J A, Kick S A, Moffat A J, Masters W M, Kon D
Department of Biology, University of Oregon, Eugene 97403.
J Acoust Soc Am. 1988 Aug;84(2):551-9. doi: 10.1121/1.396832.
The sensitivity of the echolocating bat, Eptesicus fuscus, for detection of a sonar target is impaired by the presence of additional targets located at similar distances. At a range of 54 cm, sensitivity to one target declines if the range separation to other targets is smaller than 8-9 cm. This loss of sensitivity is an example of clutter interference along the range axis, created by simultaneous masking of one set of echoes by another. Echoes that fall within an experimentally defined critical range band may sum together to contribute collectively to detection in that band. Echoes falling into separate bands may be detected independently. Acoustic glints within a band appear to be grouped together to be perceived as a single range-extended target of complex structure. Range bands may thus define what a "target" is by specifying within-target and between-target differences in range. The width of critical range bands appears to depend upon target range, with wider bands at greater ranges.
回声定位蝙蝠棕蝠（Eptesicus fuscus）对声纳目标的探测灵敏度会因存在距离相近的其他目标而受损。在54厘米的距离上，如果与其他目标的距离间隔小于8 - 9厘米，对一个目标的灵敏度就会下降。这种灵敏度的损失是距离轴上杂波干扰的一个例子，是由一组回波被另一组回波同时掩蔽造成的。落入实验定义的临界距离带内的回波可能会叠加在一起，共同对该带内的探测产生贡献。落入不同距离带的回波可能会被独立检测到。一个距离带内的声学闪烁似乎会聚集在一起，被视为一个具有复杂结构、距离扩展的单个目标。因此，距离带可以通过指定目标内部和目标之间的距离差异来定义什么是“目标”。临界距离带的宽度似乎取决于目标距离，距离越大，带宽越宽。
