3D Audio Analysis and Synthesis

• Main Authors: Kuen-Ying Ou, 歐昆應
• Other Authors: Mingsian R. Bai
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/62714532940418320367

博士 === 國立交通大學 === 機械工程系所 === 93 === The dissertation focuses on the 3D audio analysis and synthesis, which contains the research of sound source localization and room effects reproduction. Regarding to sound source localization, two approaches were developed in this work. First, an external ear model based on a three-dimensional array beamformer is presented to synthesize the head-related transfer functions (HRTF). The array coefficients are calculated by matching the measured HRTFs with a frequency-domain template. The model matching problem is then solved, by using s singular value decomposition (SVD) procedure. Second, a perceptual approach for calculating HRTFs is presented. In this method, the ratio between the contra- and ipsilateral HRTFs were represented by a lower order finite impulse response (FIR) filter on the basis of the interaural transfer functions (IATF). The FIR filter is obtained by using the Wiener filter approach. To further improve the computational efficiency, absolute threshold of human hearing is exploited to eliminate the redundancy in the HRTFs. In the research related to the room effects reproduction, an artificial reverberator is proposed to synthesize room responses. The method employs the virtual source representation and the comb-nested allpass filters to generate the early reflection and late reverberation, respectively, of room responses. The filtering property of human hearing is also exploited in a non-uniform sampling procedure to further simplify the computation. Optimal parameters of the comb-allpass filter network are obtained using the genetic algorithm (GA). All proposed methods were examined both objectively and subjectively, and had been proven to be effective in 3D audio synthesis.