Processing of simple and complex acoustic signals in a tonotopically organized ear

Processing of complex signals in the hearing organ remains poorly understood. This paper aims to contribute to this topic by presenting investigations on the mechanical and neuronal response of the hearing organ of the tropical bushcricket species Mecopoda elongata to simple pure tone signals as well as to the conspecific song as a complex acoustic signal. The high-frequency hearing organ of bushcrickets, the crista acustica (CA), is tonotopically tuned to frequencies between about 4 and 70 kHz. Laser Doppler vibrometer measurements revealed a strong and dominant low-frequency-induced motion of the CA when stimulated with either pure tone or complex stimuli. Consequently, the high-frequency distal area of the CA is more strongly deflected by low-frequency-induced waves than by high-frequency-induced waves. This low-frequency dominance will have strong effects on the processing of complex signals. Therefore, we additionally studied the neuronal response of the CA to native and frequency-...

听觉器官对复杂信号的处理机制仍未得到充分阐明。本研究旨在通过探究热带螽斯Mecopoda elongata的听觉器官对简单纯音信号，以及作为复杂声学信号的同种鸣曲的机械响应与神经元响应，为该领域的相关研究提供补充。螽斯的高频听觉器官——听嵴（crista acustica, CA）——具备拓扑频率调谐特性，其调谐频率范围约为4~70 kHz。采用激光多普勒测振仪（Laser Doppler vibrometer）开展的测量结果显示，无论施加纯音还是复杂声学刺激，听嵴均会产生由低频诱导的显著且占主导的运动。由此可知，听嵴的高频远端区域受到低频诱导波的偏转幅度，显著大于高频诱导波带来的偏转幅度。这种低频主导效应将对复杂信号的处理过程产生显著影响。因此，我们进一步探究了听嵴对原生声学信号及频率-