Roverud R C
Department of Biology, University of California, Riverside 92521.
J Comp Physiol A. 1994 May;174(5):559-65. doi: 10.1007/BF00217376.
A stereotypical approach phase vocalization response of the lesser bulldog bat, Noctilio albiventris, to artificial echoes simulating a virtual approaching object was used to assess the ability of the bat to analyze and extract distance information from the artificial echoes. The performance of the bat was not significantly different when presented with naturally structured CF/FM echoes containing FM elements that sweep continuously from about 75-55 kHz in 4 ms or with CF/FM echoes containing FM components constructed from a series of 98 pure tone frequency steps, each with a duration of 0.04 ms. The performance of the bat remained unchanged when the duration of the tone steps was increased up to 0.08 ms but declined sharply to a level that was significantly below that seen with a naturally structured echo when the steps were 0.09 ms or longer. The performance of the bat depended on the duration of the individual tone steps, which could not exceed a specific upper limit of about 0.08 ms. The study suggests that the bats have adaptations for processing individual narrow band segments of FM signals over specific time intervals.
皱唇犬吻蝠（Noctilio albiventris）对模拟虚拟接近物体的人工回声的典型趋近阶段发声反应，被用于评估蝙蝠从人工回声中分析和提取距离信息的能力。当蝙蝠面对自然结构的CF/FM回声（其中的FM元素在4毫秒内从约75 - 55千赫连续扫频）或包含由一系列98个纯音频率步长构成的FM成分的CF/FM回声（每个步长持续时间为0.04毫秒）时，其表现没有显著差异。当音步持续时间增加到0.08毫秒时，蝙蝠的表现保持不变，但当步长为0.09毫秒或更长时，其表现急剧下降至显著低于自然结构回声的水平。蝙蝠的表现取决于各个音步的持续时间，该持续时间不能超过约0.08毫秒的特定上限。该研究表明，蝙蝠具有在特定时间间隔内处理FM信号的各个窄带段的适应性。
