Satoshi Yairi

The Effects of Ambient Sounds on the Quality of 3D Virtual Sound Space

Immersive sound spaces which are synthesized using virtual reality techniques have recently been developed to realize highly realistic telecommunication interactions. In real world soundscapes the sounds we usually listen to include background or “ambient” sounds such as the sounds of the ventilation system in a room. However, current virtual auditory display systems generate point sound sources which are often attributed to specific object locations. Therefore, it is possible to reproduce sound direction, but no information about the sound space is included. As a result, the sound output is often dry and unnatural. In this research, a rendering method for ambient sounds and its effects are investigated. An optimum rendering algorithm of ambient sounds is proposed and its effects on the quality of sound space are examined.

Comparative performance evaluation of near 3D sound field reproduction system with directional loudspeakers and wave field synthesis

Near 3D sound field display systems are important toward realizing ultra-realistic communications systems such as 3D television. We have proposed the near 3D sound field reproduction systems using directional loudspeakers and wave field synthesis and developed the real system by constructing the surrounding microphone array and the radiated loudspeaker array. In this paper, to evaluate the performance of sound image localization in the developed system, sound image positions were estimated via computer simulation. The results indicated that listeners can accurately localize a sound image in any listening position around the radiated loudspeaker array if the radiation directivity of the loudspeaker units is sharpened, and that listeners can accurately localize a sound image close to the listening position if they listen to a sound in a particular listening position, even if the radiation directivity of the loudspeaker units is not sharpened. Results of estimation of a sound image position by acoustical measurement similarly showed that listeners can accurately localize a sound image close to the listening position if they listen to a sound in a particular listening position.