Design and implementation of automotive audio signal processing systems

• Main Author: 洪志仁
• Other Authors: 白明憲
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/37363152345340273849

碩士 === 國立交通大學 === 機械工程系所 === 96 === Design and implementation strategies of spatial sound processing are investigated in this paper for automotive scenarios. Ten design algorithms are implemented for various rendering modes with different number of passengers and input channels. Two up/downmixing algorithms aimed at balancing the front and rear reproduction are developed for the stereo two-channel input and the 5.1-channel input, respectively. Eight algorithms based on inverse filtering are implemented in two approaches. The first approach is based on binaural HRTFs (Head-Related Transfer Functions) measured in the car interior, which accounts for the diffraction and shadowing effect due to the head, ears and torso. In the second approach termed the point-receiver model, sound rendering is targeted at a point receiver positioned at the head center of the passenger. The proposed processing algorithms were compared via series of objective and subjective experiments under various listening conditions. In particular, a localization test was undertaken in the car interior to compare the proposed algorithms. Test data were processed by the multivariate analysis of variance (MANOVA) and the least significant difference method (Fisher’s LSD) as a post hoc test to justify the statistical significance. The results indicate that inverse filtering methods are preferred for the single passenger mode. For the multi-passenger mode, however, up/downmixing algorithms have attained better performance than the other processing techniques.