Conversion of Multichannel Sound Signal Maintaining Physical Properties of Sound in Reproduced Sound Field

• Published in: IEEE transactions on audio, speech, and language processing Vol. 19; no. 6; pp. 1467 - 1475
• Main Author: Ando, A
• Format: Journal Article
• Language: English
• Published: Piscataway, NJ IEEE 01.08.2011; Institute of Electrical and Electronics Engineers
• Subjects: Acoustic signal processing; Applied sciences; Channels; Conversion; Detection, estimation, filtering, equalization, prediction; Equations; Exact sciences and technology; Fourier transforms; Frequency conversion; Information, signal and communications theory; Loudspeakers; Mathematical analysis; Miscellaneous; Multichannel; Phantoms; Physical properties; Signal and communications theory; Signal processing; Signal, noise; Sound; sound field reproduction; Sound fields; sound localization; spatial and multichannel audio; Telecommunications and information theory; three- dimensional sound; Timbre; Sound reproduction; Acoustic signal; Partition method; Acoustic signal detection; Acoustic signal processing; three-dimensional sound; Loudspeaker; Low frequency; Physical properties; Subjective evaluation; spatial and multichannel audio; Three dimensional model; Audio signal; sound field reproduction; Linear equation; Audio systems; sound localization; Analytical method; Audio acoustics; Signal conversion; Multiple channel; Test object
• ISSN: 1558-7916; 1558-7924
• DOI: 10.1109/TASL.2010.2092429

In this paper, we describe a new method for converting the signal of the original multichannel sound system into that of an alternative system with a different number of channels while maintaining the physical properties of sound at the listening point in the reproduced sound field. Such a conversion problem can be described by the underdetermined linear equation. To obtain an analytical solution to the equation, the method partitions the sound field of the alternative system on the basis of the positions of three loudspeakers and solves the "local solution" in each subfield. As a result, the alternative system localizes each channel signal of the original sound system at the corresponding loudspeaker position as a phantom source. The composition of the local solutions introduces the "global solution," that is, the analytical solution to the conversion problem. 22-channel signals of a 22.2 multichannel sound system without the two low-frequency effect channels were converted into 10-, 8-, and 6-channel signals by the method. Subjective evaluations showed that the proposed method could reproduce the spatial impression of the original 22-channel sound with eight loudspeakers.