Heffner Rickye S, Koay Gimseong, Heffner Henry E
Department of Psychology, University of Toledo, Toledo, OH 43606, USA.
Hear Res. 2003 Oct;184(1-2):113-22. doi: 10.1016/s0378-5955(03)00233-8.
We determined the audiogram of the Jamaican fruit-eating bat (Phyllostomidae: Artibeus jamaicensis), a relatively large (40-50 g) species that, like other phyllostomids, uses low-intensity echolocation calls. A conditioned suppression/avoidance procedure with a fruit juice reward was used for testing. At 60 dB SPL the hearing range of A. jamaicensis extends from 2.8 to 131 kHz, with an average best sensitivity of 8.5 dB SPL at 16 kHz. Although their echolocation calls are low-intensity, the absolute sensitivity of A. jamaicensis and other 'whispering' bats does not differ from that of other mammals, including other bats. The high-frequency hearing of A. jamaicensis and other Microchiroptera is slightly higher than expected on the basis of selective pressure for passive sound localization. Analysis suggests that the evolution of echolocation may have been accompanied by the extension of their high-frequency hearing by an average of one-half octave. With respect to low-frequency hearing, all bats tested so far belong to the group of mammals with poor low-frequency hearing, i.e., those unable to hear below 500 Hz.
我们测定了牙买加果蝠（叶口蝠科：美洲果蝠）的听力图，该物种相对较大（40 - 50克），与其他叶口蝠一样，使用低强度的回声定位叫声。测试采用了以果汁为奖励的条件性抑制/回避程序。在60分贝声压级下，美洲果蝠的听力范围从2.8千赫延伸至131千赫，在16千赫时平均最佳灵敏度为8.5分贝声压级。尽管它们的回声定位叫声强度较低，但美洲果蝠和其他“低语”蝙蝠的绝对灵敏度与包括其他蝙蝠在内的其他哺乳动物并无差异。美洲果蝠和其他小蝙蝠亚目的高频听力略高于基于被动声音定位的选择压力所预期的水平。分析表明，回声定位的进化可能伴随着它们高频听力平均扩展了半个八度。关于低频听力，迄今为止测试的所有蝙蝠都属于低频听力较差的哺乳动物群体，即那些无法听到低于500赫兹声音的动物。
