1. 1) M. Katsumoto, Y. Yamakata and T. Kimura, "Spatial audio technology," J. Natl. Inst. Inf. Commun. Technol., 57, 97–104 (2010).
2. 2) K. Maki, T. Kimura and M. Katsumoto, "Reproduction of sound radiation directivities of musical instruments by a spherical loudspeaker with multiple transducers," Proc. 9th Int. Conf. Virtual-Reality Contin. Its Appl. Ind. (VRCAI), pp. 85–88 (2010).
3. 3) K. Maki, T. Kimura and M. Katsumoto, "Reproduction of real musical instrument sounds by a spherical loudspeaker with 26 transducers: Acoustic comparison on reproducibility of sound radiation patterns of musical instruments," J. Acoust. Soc. Jpn. (J), 67, 447–458 (2011) (in Japanese).
4. 4) K. Maki, T. Kimura and M. Katsumoto, "Sound radiation characteristics of a spherical loudspeaker with 42 transducers: Reproduction of sound of a real violin performance," Proc. Spring Meet. Acoust. Soc. Jpn., pp. 893–896 (2011) (in Japanese).
5. 5) K. Maki, T. Kimura and M. Katsumoto, "Spatial radiation pattern of sound from a violin played by a violist," IEICE Tech. Rep., 111, pp. 71–76 (2011) (in Japanese).