Activc Noisc Control (ANC) systcm formed of a corner microphone-amplifier-loudspeaker system has been shown cffcchve to rcduce the reverberant noise in a room bascd on the normal-mode-canccling principle, and the theo...Activc Noisc Control (ANC) systcm formed of a corner microphone-amplifier-loudspeaker system has been shown cffcchve to rcduce the reverberant noise in a room bascd on the normal-mode-canccling principle, and the theory and practicc of such has also been clarified. But steady state noisc are considered only in the past, and few cascs arc stable noise sources, and there is time that cven the stable noise sources are started or stopped. Any change of the noise source will excite transient in thc ANC system,which might have unfavorab1c effect on the application of thc ANC system. It is desirable to have a good knowledge of the transient behavior on thc ANC system in order to effect a better utilization of it. It is the purpose of this investiga tion to clarify the transient behavior of the ANC system in a room and the influence on its acoustics.展开更多
Aerodynamic characteristics, the noise characteristics in the course of intermittence exhaust are investigated and the expressions for sound pressure level of the noise generated by single-pole source and quadrupole s...Aerodynamic characteristics, the noise characteristics in the course of intermittence exhaust are investigated and the expressions for sound pressure level of the noise generated by single-pole source and quadrupole source in the intermittence exhaust noise are established. The effects of all parameters in pneumatic system on the noise are also comprehensively studied.展开更多
文摘Activc Noisc Control (ANC) systcm formed of a corner microphone-amplifier-loudspeaker system has been shown cffcchve to rcduce the reverberant noise in a room bascd on the normal-mode-canccling principle, and the theory and practicc of such has also been clarified. But steady state noisc are considered only in the past, and few cascs arc stable noise sources, and there is time that cven the stable noise sources are started or stopped. Any change of the noise source will excite transient in thc ANC system,which might have unfavorab1c effect on the application of thc ANC system. It is desirable to have a good knowledge of the transient behavior on thc ANC system in order to effect a better utilization of it. It is the purpose of this investiga tion to clarify the transient behavior of the ANC system in a room and the influence on its acoustics.
基金Special Fund for the Whole Nation Excellent Doctorate Thesis of the Colleges and University of China.
文摘Aerodynamic characteristics, the noise characteristics in the course of intermittence exhaust are investigated and the expressions for sound pressure level of the noise generated by single-pole source and quadrupole source in the intermittence exhaust noise are established. The effects of all parameters in pneumatic system on the noise are also comprehensively studied.
