噪声控制技术和设备的发展现状和展望

本文主要介绍噪声控制工程和设备的评价技术、噪声控制技术的规范化、噪声控制技术的计算机辅助工具、声学材料和噪声设备等领域的国内外发展现状，并对我国上述领域今后的发展提出了一些建议。  

噪声主动控制研究的发展与动向

本回顾了噪声主动控制的典型设计方法和常见的算法，结合当前较新的鲁棒控制方法，指出今后噪声主动控制的一些发展动向，为这一技术的实用性提供借鉴。  

Self-induced stochastic resonance in excitable systems

The effect of small-amplitude noise on excitable systems with strong time-scale separation is analyzed. It is found that vanishingly small random perturbations of the fast excitatory variable may result in the onset of a deterministic limit cycle behavior, absent without noise. The mechanism, termed self-induced stochastic resonance, combines a stochastic resonance-type phenomenon with an intrinsic mechanism of reset, and no periodic drive of the system is required. Self-induced stochastic resonance is different from other types of noise-induced coherent behaviors in that it arises away from bifurcation thresholds, in a parameter regime where the zero-noise (deterministic) dynamics does not display a limit cycle nor even its precursor. The period of the limit cycle created by the noise has a non-trivial dependence on the noise amplitude and the time-scale ratio between fast excitatory variables and slow recovery variables. It is argued that self-induced stochastic resonance may offer one possible scenario of how noise can robustly control the function of biological systems.  

从建筑声学到环境声学

本文简述环境声学的发展过程以及在厅堂音质、环境噪声和噪声控制方面的新世纪展望。  

声屏障和有源噪声控制声屏障

概述了声屏障降低噪声的原理和常用方法，提出了存在的不足，介绍了有源声屏障的降噪性能与发展动态，提出了进一步研究的设想。  

Mechanisms of active control of sound transmission through a linked double-wall system into an acoustic cavity

The mechanism of active control on sound transmission through a mechanically linked double-wall structure into an acoustic cavity is investigated in this paper. Two control methods, i.e., structural control and acoustic control under two linkage cases (soft and hard) are investigated to analyze the effect of the links on the selection of control strategies and the corresponding control mechanisms. Simulations are performed to examine the dominant control mechanism (modal suppression or modal rearrangement) in different frequency ranges for each control case. The alteration in the structural-acoustic coupling is also analyzed so as to explain the mechanisms of sound attenuation. In addition, the dominance of the acoustic mode (0, 0, 0) in the energy transmission process as well as its use in designing a more effective sensor/actuator arrangement is discussed.  

反馈有源噪声控制系统水床效应的分析与改善

本文依据反馈有源噪声控制原理分析了水床效应存在机理,以一模拟反馈有源噪声控制系统作为实例介绍了水床效应的分析方法,提出了通过展宽噪声放大频段和均匀噪声放大频段内的噪声放大量来优化反馈控制器,改善水床效应的方法。采用数字反馈控制器实现了水床效应的改善,给出了具体设计过程,并且考虑了数字时延对系统性能影响。仿真和实验表明了所提出方法的有效性。  

Performance of noise barriers with various edge shapes and acoustical conditions

The performances of barriers having different shapes and surface conditions were tested using the boundary element method in a well-controlled environment. The heights and widths of the barriers were standardized and the insertion losses for six receiver positions were averaged and compared. Figures displaying the results allow for straightforward barrier performance estimation. It was shown that absorbing and soft edges significantly improve the efficiency of the barrier, but configuration modifications provide only a slight improvement. The soft T-shaped barrier produces the highest performance. A 3 m high T-shaped barrier provides the same performance as a 10 m high plain barrier. The spectral efficiency was also investigated. The insertion loss spectra for the absorbing and the soft barriers exhibit a similar shape, but the rigid barrier differs from these two.  

墨粉灌装车间噪声测试分析与控制

本文应用峰值频率声压级对比方法并结合相干分析技术对某墨粉灌装车间主噪声源进行了诊断，分析了声源特性，在此基础上提出了经济合理的治理措施，实施后取得了满意的结果，车间噪声达到了相应的国家标准。  

主动噪声控制声学通道的实验辨识

传统的自适应滤波器不能直接用于主动噪声控制，因为扬声器和误差传声器之间的声学通道可能使系统不稳定。本文根据声学通道的相应特性，建立补偿滤波器，提出了用实验方法辨识声学通道传输特性。在房间实验中研究了单通道相位因子的变化特性，并进一步用于飞机人多通道主动噪声控制，给出了相应的实验结果。