Active Noise-proof Window Aimed At Electronic Music Noise

Electronic music noise,such as square dance music,makes a great impact on residents' life and health.At present,the main control of outdoor electronic music noise is prohibiting noisy activity.But this way is lack of reality,which will cause great disturbance to people's social activities.The noise mainly comes into the room from the window.Some scholars study insulation window from the angle of passive noise control,but the noise reduction effect of low frequency noise is not obvious.In order to solve this problem,the active noise control system is introduced into the interlaced sound insulation window.First,a simplified sound field model of active sound insulation window is established for the characteristics of electric noise.The vibration frequency in sound insulation window is obtained by using one dimensional pipe acoustic theory,which is 1143.2Hz.When the vibration frequency of the source is smaller than the cut-off frequency of the duct,the traveling wave of uniform plane can only propagate in the tube.Based on the above models,the active sound insulation window control system is designed and simulated.In this paper,a single channel feedforward control system is chosen as the control mode,and the adaptive algorithm is the FxLMS algorithm.Through Matlab simulation,the system has a noise reduction effect on the mixed noise of 200 Hz and white noise,and the influence of different filter length,convergence coefficient and primary source frequency on the performance of the algorithm is compared and analyzed.The last part is the physical experiment.The experiment system includes hardware design and software design.DSP chip is selected as the active control system controller and the software is designed in the C language.Through the noise control experiment of active sound insulation window,the average noise reduction of 7.7dB can be achieved in real environment.The influence of the distance between the reference sensor and the primary sound source on the noise reduction,and the influence of the distance between the error sensor and the secondary sound source on the noise reduction are experimentally verified.The influence of the distance between the reference sensor and the primary sound source on the noise reduction,and the influence of the distance between the error sensor and the secondary sound source on the noise reduction are experimentally verified.The experimental results show that when the reference sensor gradually gets away from the inlet of the inlet,the noise reduction is increasing and the distance of the reference sensor to the primary sound source is increased.The noise reduction pressure value of the system gradually decreases;the distance of the error sensor to the secondary sound source becomes larger and the noise reduction of the active sound insulation window decreases gradually.