短翅鸣螽的鸣声特征分析与听觉研究

本文利用声分析方法研究了短翅鸣螽Gampsocleis gratiosa鸣声的结构、频谱与时域特征。短翅鸣螽主要靠复翅闭合运动时左翅腹面上的音锉与右翅内缘(刮器)相摩擦而发声。音锉脉冲声列是短翅鸣螽鸣声的基本组分,它由一个开翅脉冲和6—7个闭翅脉冲组成。鸣声的频谱较宽,声能主要分布在3—35kHz范围内;主、次能峰分别位于7.5kHz与4.0kHz附近,在10cm远处鸣声强度L_p约为105dB。鸣声的时域特征与环境温度有关。鸣声的三维数字功率谱图分析揭示了频谱能峰的瞬时变化特征。鸣螽有较高的听觉灵敏度,在与其鸣声主能峰区相应的频率范围内(7—18kHz),反应阈值均在30dBL_p以下。螽斯的听觉神经元能对其鸣声的时域特征进行编码。

A study of song characteristics and hearing of the bushcricket Gampsocleis gratiosa

The structure, power spectrum and temporal parameters of the calling song of the bushcricket Gampsocleis gratiosa were studied with acoustic analysis techniques. The bushcricket uses an elytro-elytral mechanism in sound production: the denticulated vein (file) on the under-surface of the left elytron is rubbed by the inside edge of the right elytron (plectrum). The file-train of pulses is the element of the calling song. Each file-train of pulses is composed of one elytra-opening pulse and 6-7 elytra-closing tooth pulses. The power spectrum of the song covers a wide frequency band. The acoustic energy is mainly distributed in the f equency range between 3 and 35 kHz. The predominant peak lies near 7.5 kHz and the next one around 4.0 kHz. The song intensity is measured of about 105 dB L_p at a distance of 10 cm from the animal. The temporal parameters of the song are dependent on the ambient temperature. Three-dimentional digital spectrograms of the song show its dynamic changes of the energy peaks. The bu hcricket is very sensitive to acoustic stimuli and its thresholds are less than 30 dB L_p in the frequency zone from 7 to 18 kHz, which corresponds to the dominant energy range. The auditory neurons of the bushcricket can code the temporal parameters of the calling song.