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

为掌握水上鸟类栖息地的分布和声学特征，开展了基础性研究，取得了以下主要成果：(1)通过对水上鸟类辐射的声学信号的自动记录和分析，发现大多数鸟类发出超声波范围内的信号，同时也发出音频信号。(2)记录的鸟鸣音频信号约为20盘DAT磁带，(3)通过计算机网络将新引进的高速工作站与我所现有的系统连接起来，构成了高灵活性、高速度的在线信号处理系统。(4)将测量的鸟鸣的二、三阶频谱和语音分析得到的二维和三维频谱模式信息压缩为简单形式的向量，并用判别分析和神经网络对得到的14种向量进行判别。(5)人工信号对鸟类听觉味觉的研究表明，鸟类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.