黑蝉(C.Atrata Fabricius.)发声声学的研究

A stuty on sound production acoustics in the black cieada (C. Atrata Fabricius.)

黑蝉发声膜的长肋可类比为一端夹紧的梁,激励声的基频为3900—5500Hz,与黑蝉鸣声的主峰频率(MPF)的可能范围基本一致。有盖(Op)、鼓盖(TC)和褶膜(JM)可分别类比为一边固定、二边固定其余自由的均匀方板和四边固定的矩形膜,受激振动的基频(f_(OP)~1=940Hz、f_(TC)~1=1200Hz和f_(JM)~1=810Hz),及其f_(OP)^(3,4.5,5,5.5,6)、f_(TC)^(2,2.5,3,3.5)和f_(JM)^(45,65,66,76,77)分别与Op、TC和JM振动的MPF及其主要高频成分基本相一致,共鸣腔和两侧气门可类比为并联谐振电路和并接于输出端的电阻,谐振频率和品质因素与黑蝉鸣声的MPF和调谐度基本相一致。

The long rib of the sounding membrane in the black cicada is an analog to a beam clamped at one end. The fundamental frequency of the activated sound is between 3900-5500 Hz, basically consistent with the possible renge of the main peak frequency (MPF) of the song in the black cicada. The operculum (Op), tymbal cover (TC) and joint membrane (JM) are respectively analogous to a uniform square plate clamped at one edge and free at the others, to another plate clanped at two opposite sides and free at the other two, and to a rectangular membrane clamped at four sides. The fundamental frequencies of activated vibration (f1op=940Hz, f1Tc=1200Hz, and f1JM=810Hz) and f3,4,5,5,5.5,6OP,f2, 2,2.5,3,3.5TC and f4,,65,66,76,77JM ara basically consistent with the MPFs and main high frequency components of vibrations of the Op, TC and JM, respectively. The resonant cavity and spiracles on both sides are analogous to a resonace circuit with a resistor connected in parallel at the output terminall, and the resonant frequency and quality factor of the circuit are in good agreement with the MPF and its tuning sharpness of the song in the black cicada.