Padgham Mark
Department of Zoology, The University of Melbourne, Australia 3010.
J Acoust Soc Am. 2004 Jan;115(1):402-10. doi: 10.1121/1.1629304.
Rates of reverberative decay and frequency attenuation are measured within two Australian forests. In particular, their dependence on the distance between a source and receiver, and the relative heights of both, is examined. Distance is always the most influential of these factors. The structurally denser of the forests exhibits much slower reverberative decay, although the frequency dependence of reverberation is qualitatively similar in the two forests. There exists a central range of frequencies between 1 and 3 kHz within which reverberation varies relatively little with distance. Attenuation is much greater within the structurally denser forest, and in both forests it generally increases with increasing frequency and distance, although patterns of variation differ between the two forests. Increasing the source height generally reduces reverberation, while increasing the receiver height generally reduces attenuation. These findings have considerable implications for acoustic communication between inhabitants of these forests, particularly for the perching behaviors of birds. Furthermore, this work indicates the ease with which the general acoustic properties of forests can be measured and compared.
在澳大利亚的两片森林中测量了混响衰减率和频率衰减率。特别地，研究了它们对声源与接收器之间距离以及两者相对高度的依赖性。距离始终是这些因素中最具影响力的。结构更密集的森林表现出慢得多的混响衰减，尽管混响的频率依赖性在这两片森林中在定性上是相似的。在1至3千赫兹之间存在一个中心频率范围，在这个范围内混响随距离的变化相对较小。在结构更密集的森林中衰减要大得多，并且在两片森林中衰减通常都随着频率和距离的增加而增加，尽管两片森林中的变化模式有所不同。增加声源高度通常会减少混响，而增加接收器高度通常会减少衰减。这些发现对这些森林中生物的声学通信具有重要意义，特别是对于鸟类的栖息行为。此外，这项工作表明测量和比较森林的一般声学特性是多么容易。
