Personal Sound Control In A Car Cabin And Research On Accelerating Sound Quality

Personal sound control and accelerating sound quality in a car cabin are investigated in order to satisfy the diversified demand of vehicle acoustic environment from consumers.Researches on optimizing the configuration of the loudspeaker array,controlling the performance of personal sound,quantifying the subjective preference of accelerating sound quality,extracting the objective parameters corresponding with the subjective preference,building and analyzing the predicted model of preferred accelerating sound quality and so on are investigated in order to provide various acoustic environments for consumers,which is remarkably meaningful and applicable for improving vehicle acoustic comfort.In order to achieve an optimized configuration of the loudspeaker array for personal sound control,considering minimization of number of loudspeakers and optimization of control performance of personal sound at the same time,a method for investigating the optimized symmetrical loudspeaker array is proposed.In the process of calculating control performance,the model of each source is made up of multi-monopoles all driven in phase to simulate the effect that a loudspeaker with a finite size results in an increasing directivity at the high frequencies in the practical application.In order to control the performance of personal sound,a robust method within the frequency domain,PSR-RC,is proposed to balance the reproductive performance of the bright zone and the acoustic energy in the dark zone.Convolution filtering is applied to achieve the transformation from the driving signals of loudspeaker array in the frequency domain to that in the time domain.Personal sound control system within the front zone or the rear zone in a car cabin is designed and built.Relevant experimental results shows that the proposed ceiling-mounted symmetrical source array with 8 loudspeaker can achieve a personal sound control within the front zone or the rear zone in the frequency bandwidth between 200Hz and 10kHz.Along with a clearly audible sound within the bright zone,a satisfied acoustic contrast between the bright and dark zone is achieved using PSR-RC method.The off-line simulated results match the real-time experimental results well,which shows that the robustness of personal sound control system is achieved.In order to quantify the subjective preference of accelerating sound quality,fuzzy reconstructed method is proposed to quantify the subjective evaluation results using grouped pair-wise comparison.The subjective evaluation experiment with sound samples of 2GWOT(Wide Open Throttle of 2^nd Gear)and 3GWOT?Wide Open Throttle of 3^rdd Gear?for preference is conducted.After completing validation and clustering of the experimental data,two main accelerating subjective preference are shown.Considering the psychoacoustic parameters and typical accelerating order characteristics,objective parameters corresponding with the accelerating subjective preference are proposed through correlation analysis.In order to put forward and analyze the predicted model for accelerating subjective preference,subjective parameters are as input and support vector regression algorithm is applied.The two accelerating subjective preference is classified as luxury sound quality and sporty sound quality,and then the design directions of the two accelerating preferred sound quality are investigated through the quantitative analysis of the relationship between accelerating subjective preference and objective parameters.Some accelerating sound samples are modified and then compared with the original accelerating sound samples.Relevant experimental results verified the predicted model and the design direction of accelerating subjective preference.