Physical acoustic characteristics of earphones and headphones required for the faithful reproduction of the original spatial impression of immersive binaural sound
Immersive sound has been developed for systems with multichannel loudspeakers arranged in three dimensions, such as the 22.2 multichannel sound system. Recently, more and more immersive sound content is being produced to be listened to with headphones and earphones so that the immersive sound content can be enjoyed in a simpler way. However, the differences between the spatial impression reproduced by multichannel loudspeakers and that reproduced by headphones or earphones have become a problem. Representative examples of research conducted to address this problem include the individualization of head-related transfer functions used in binaural rendering and head tracking. Meanwhile, there has been less research on the physical acoustic characteristics required for earphones and headphones that reproduce the immersive binaural sound. We therefore investigated the physical acoustic characteristics of earphones and headphones required to reproduce the spatial impression of binaural sound aimed at by immersive sound content as faithfully as possible, and we found desirable characteristics. Subjective evaluation experiments showed that earphones and headphones designed according to these characteristics reproduce the spatial impression of the sound content more faithfully than devices designed on the basis of other characteristics. This workshop will introduce the appropriate physical acoustics characteristics of earphones and headphones for immersive binaural sound listening with some demos.