In the natural song of the mottled cicada, the prelude and loud song of the prolonging and repctition songs consist separatcly of several pulses containing the three subpulscs (SP1-3). The principal frequencies (PFban...In the natural song of the mottled cicada, the prelude and loud song of the prolonging and repctition songs consist separatcly of several pulses containing the three subpulscs (SP1-3). The principal frequencies (PFband PFc) of the basic sound and carricr frcquency band are 338±20 Hz and 3617±87 Hz, respectively.The prelude or the prolonging song contains 22 pulses (P1-22),and their amplitude-modulation propertics gradually decay. The carrier-wave oscillations gradually lose symmetrics and overlap with basic waves of the SP1, and the SP2,3 are similar to sine waves. Moreover, a dominant tone of the song gradually changes from PFc into PFb. In the loud song of the prolonging song, the prelude and loud song of repetition songs, the amplitude-modulation propcrties are lost.The carrier-wave oscillations mainly overlap with basic waves of the SP2, and the amplitudes of the PFc arc 10 dB over lower than those of the PFb, and the songs are the PFb of basic sounds as a dominant tone. In view of the structure of the sounding membrane, the vibration frequencies of the three long ribs may be gradually changed from mass controlling to mechanical resistance controlling, and corresponding songs are gradually changed from the prolonging prelude with the PFc as a dominant tone to the loud song and repetition songs with the PFb as a dominant tone.展开更多
文摘In the natural song of the mottled cicada, the prelude and loud song of the prolonging and repctition songs consist separatcly of several pulses containing the three subpulscs (SP1-3). The principal frequencies (PFband PFc) of the basic sound and carricr frcquency band are 338±20 Hz and 3617±87 Hz, respectively.The prelude or the prolonging song contains 22 pulses (P1-22),and their amplitude-modulation propertics gradually decay. The carrier-wave oscillations gradually lose symmetrics and overlap with basic waves of the SP1, and the SP2,3 are similar to sine waves. Moreover, a dominant tone of the song gradually changes from PFc into PFb. In the loud song of the prolonging song, the prelude and loud song of repetition songs, the amplitude-modulation propcrties are lost.The carrier-wave oscillations mainly overlap with basic waves of the SP2, and the amplitudes of the PFc arc 10 dB over lower than those of the PFb, and the songs are the PFb of basic sounds as a dominant tone. In view of the structure of the sounding membrane, the vibration frequencies of the three long ribs may be gradually changed from mass controlling to mechanical resistance controlling, and corresponding songs are gradually changed from the prolonging prelude with the PFc as a dominant tone to the loud song and repetition songs with the PFb as a dominant tone.
