Tuning the drum: the mechanical basis for frequency discrimination in a Mediterranean cicada
Tuning the drum: the mechanical basis for frequency discrimination in a Mediterranean cicada
复制标题
调鼓：地中海蝉频率辨别的机械基础
DOI：
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发表时间：
2006
影响因子：
2.8
通讯作者：
D. Robert
中科院分区：
文献类型：
--
作者：
J. Sueur;J. Windmill;D. Robert
知了知了用声音来寻找配偶。虽然雄蝉用来发出响亮叫声的机制已经被详细描述，但很少有信息解释它们的耳朵是如何工作的。利用微扫描激光多普勒测振仪，测量了蝉的鼓室振动对声学回放的响应。精确的光学测量揭示了解剖结构复杂的鼓膜的振动行为。值得注意的是，鼓膜脊是鼓膜的一个独特的结构元素，是连接感受器细胞的纽带，经历着让人想起行波的机械振动。实际上，观测到最大偏转幅度的频率从脊顶到脊底有规律地递减。研究还表明，虽然女性的耳朵会机械地调谐到男性的歌声中，但男性的鼓膜只会部分调谐到自己的歌声中。这项研究建立了一种可能处理听觉频率分析的外围听觉机制的存在。鉴于声音信号在蝉中的重要性，这种非传统的鼓膜机制可以用于物种识别和性别选择。
SUMMARY Cicadas are known to use sound to find a mate. While the mechanism employed by male cicadas to generate loud calling songs has been described in detail, little information exists to explain how their ears work. Using microscanning laser Doppler vibrometry, the tympanal vibrations in the cicada Cicadatra atra are measured in response to acoustic playbacks. The topographically accurate optical measurements reveal the vibrational behaviour of the anatomically complex tympanal membrane. Notably, the tympanal ridge, a distinct structural element of the tympanum that is a link to the receptor cells, undergoes mechanical vibrations reminiscent of a travelling wave. In effect, the frequency for which the maximum deflection amplitude is observed regularly decreases from the apex to the base of the ridge. It is also shown that whilst female ears are mechanically tuned to the male's song, the male's tympanum is only partially tuned to its own song. This study establishes the presence of a peripheral auditory mechanism that can potentially process auditory frequency analysis. In view of the importance of acoustic signalling in cicadas, this unconventional tympanal mechanism may be employed in the context of species recognition and sexual selection.