Bennet-Clark HC, Daws AG
Department of Zoology, Oxford University, South Parks Road, Oxford OX1 3PS, UK and Department of Zoology, University of Melbourne, Parkville, Victoria 3052, Australia. henry.bennet-clark@zoology. oxford.ac.uk.
J Exp Biol. 1999 Jul;202 (Pt 13):1803-17. doi: 10.1242/jeb.202.13.1803.
The anatomy of the paired tymbal muscles of Cyclochila australasiae was described. Force-distance relationships of the sound-producing in-out cycle of tymbal movement were measured. The largest forces were measured when the push occurred at the apodeme pit on the tymbal plate at angles similar to the angles of internal pull of the tymbal muscle. Initially, inward movement was opposed by the elasticity of the tymbal, which stored energy. At a mean force of 0. 38 N after a mean inward strain of 368 microm, the tymbal ribs buckled, the mean energy release being 45.1 microJ. The energy release occurred over 2-10 ms in three or four sound-producing steps as successive tymbal ribs buckled inwards. After the ribs had buckled, the force decreased to a mean value of 0.17 N. The force returned to zero during the outward movement, during which the tymbal ribs buckled outwards. The mean energy dissipated in the outward movement was 32.8 microJ. During contraction, the tymbal muscle produced mean values for the peak active force of 0.31 N over 295 microm, which gave mean values for the area of the work loops of 47.0 microJ. The calling song of C. australasiae had a mean pulse rate of 234 Hz (117 Hz for each side of the insect). The peak power to mean power ratio for the songs was 8.51:1 (+9.30 dB). Measurements of the sound field around tethered insects and of the peak power to mean power ratio of the songs gave values for the mean power of the song of 3.15-7 mW; these correspond to an energy per song pulse of 13.5-30 microJ. Previously reported mean values are 3. 15 mW for protest song and 5.1 mW for calling song. The efficiency of transduction of mechanical energy into sound energy is between 18 and 46 %.
描述了澳大利亚环唇叩甲成对鼓膜肌的解剖结构。测量了鼓膜运动产生声音的进出循环的力-距离关系。当推力作用于鼓膜板上的肌腱窝，且角度与鼓膜肌向内拉力的角度相似时，测量到的力最大。最初，向内运动受到鼓膜弹性的阻碍，鼓膜弹性储存了能量。在平均向内应变368微米后，平均力为0.38牛时，鼓膜肋条弯曲，平均能量释放为45.1微焦。能量释放在2至10毫秒内分三或四个发声步骤发生，因为连续的鼓膜肋条向内弯曲。肋条弯曲后，力降至平均值0.17牛。在向外运动期间力恢复到零，在此期间鼓膜肋条向外弯曲。向外运动中耗散的平均能量为32.8微焦。在收缩过程中，鼓膜肌在295微米上产生的峰值主动力平均值为0.31牛，这使得功环面积的平均值为47.0微焦。澳大利亚环唇叩甲的求偶鸣声平均脉冲率为234赫兹（昆虫每侧117赫兹）。鸣声的峰值功率与平均功率之比为8.51:1（+9.30分贝）。对束缚昆虫周围声场以及鸣声的峰值功率与平均功率之比的测量给出了鸣声平均功率的值为3.15 - 7毫瓦；这些对应于每个鸣声脉冲的能量为13.5 - 30微焦。先前报道的抗议鸣声平均值为3.15毫瓦，求偶鸣声平均值为5.1毫瓦。机械能转换为声能的效率在18%至46%之间。
