Consideration of Effective Acoustic Rendering of Spatialized Ambient Sound

Three-dimensional sound auralization systems have been developed actively in the last few decades. Such systems are called virtual auditory displays (VADs). In conventional VADs based on head-related transfer functions (HRTFs), a sound source position alone is rendered by disregarding other acoustical phenomena. However, because various sounds surround us in our daily life, we usually hear not only a targeted direct sound but also ambient sounds in an actual sound space. A lack of ambient sound often engenders an unnatural perception of the virtual auditory space presented by VAD based on HRTFs. Therefore, ambient sounds should be included in the VAD system auralization. We investigated an effective rendering method of ambient sound using ordinary colored noise. Furthermore, using subjective evaluations, we discuss the relation between the realism of sound space with ambient sounds and a listener’s head movement.