Estimation of dwelling distribution of birds in water sites and investigation of their acoustic tastes by means of acoustical engineering and their applications

为了掌握水域鸟类的栖息地分布，并利用声学工程学的方法研究其声品味，本研究进行了基础性研究，取得了以下主要成果：（1）对水域鸟类辐射到超声波范围内的声信号进行了自动记录和分析，明确了水域鸟类除了发出声频信号外，还发出大部分超声波范围内的声信号。(2)录得的鸟鸣声信号相当于约20盘DAT磁带，每盘磁带的时长为2小时。(3)将新引进的高速工作站通过计算机网络与我所现有系统连接，构成了高度灵活、高速的在线信号处理系统。(4)将实测鸟鸣声的二阶和三阶谱分析得到的二维和三维谱型信息压缩为简单形式的矢量，并利用判别分析和神经网络对得到的14种矢量进行判别。后者比前者提供了更正确的区分率。(5)通过人工信号辐射对鸟类的听觉品味的研究表明，鸟类似乎对突发信号比平稳信号更敏感。

To grasp dwelling distribution of birds living in water sites and investigate their acoustic tastes by means of acoustical engineering, basic researches were carried out and the following main results are obtained :(1) From automatic recording and analysis of acoustical signals, up to ultrasonic range, radiated from birds living in water sites, it is made clear that most of the birds emit signals in ultrasonic range as well as audio one.(2) Recorded audio signals of bird songs amount to the quantity of about 20 DAT tapes, each of which being for 2 hours.(3) On-line signal processing system of highly flexible and high speed was constructed by connecting a newly introduced high speed work station with the existing system in our institute by way of computer networks.(4) 2D and 3D spectral pattern information obtained from the 2nd and 3rd order spectral and speech analyzes of measured bird songs was compressed as vectors of simple forms, and the resultant 14 kinds of vectors were discriminated by discriminant analysis and neural network. The latter provides the more correct discrimination rates than the former.(5) Investigation of acoustic tastes of the birds through radiation of artificial signals shows that birds seem to be more sensitive to burst signals than to stationary ones.