Angular resolution of radiation characteristics required to reproduce uttered speech in all three-dimensional directions

Abstract

For applications in six-degrees-of-freedom (6DoF) content reproduction, this study investigates the angular resolution of radiation characteristics required to reproduce uttered speech in all three-dimensional (3D) directions as an angle at which humans are unable to perceive a difference in the comprehensive audio quality change between adjacent radiation directions. The radiation characteristics of uttered Japanese speech for female and male speakers are measured in three crosssections, namely the horizontal, median, and frontal planes. The measurements are obtained using a spherical jig for 3D microphone arrangement. A subjective evaluation is conducted to clarify the impact of the difference in the radiation directions on the audio quality of uttered speech in each crosssection. Finally, a statistical analysis of the experimental results shows that the required angular resolutions are 30 relative to the horizontal plane, 30 relative to the median plane, and 60 relative to the frontal plane. Therefore, it is concluded that an angular resolution of at least 30 is required to reproduce uttered speech in all 3D directions.