Satoshi Oode

Control of a sound image to the rearward direction using band-stop filters and laterally located loudspeakers

The ability to control the sound image to the rearward direction using front or lateral loudspeakers is an important step to popularize multichannel 3D audio systems in the home environment. Rear “directional bands” were found for narrow-band signals which are perceived only in the rearward direction, but any kind of directional bands for wide-band signals, which are perceived only in the rearward direction, have not been reported. It is known that spectral notches in head-related transfer functions are important cues for a sound image localization in the median plane. In the present study, the possibility of sound image control to the rearward direction was investigated using wide-band noise of which frequency components adjacent to the rear directional bands were eliminated. A total of 56 kinds of band-stop filters were used to eliminate one to the ten consecutive 1/3-octave bands with center frequencies of 1.6 to 12.5 kHz. In-phase stimuli were emitted from a pair of loudspeakers located at azimuth ang...

Estimation of Kandoh Degree with Emphasis on Spatial Sound Impressions

It has recently been recognized that a method of evaluating audio-visual systems from the viewpoint of Kansei information is necessary for the development of high-presence audio-visual equipment. In this work, it is shown that the Kandoh, which is one aspect of Kansei information that considers various emotions, evoked by audio materials depends on the channel configuration of multichannel audio (MCA). Audio materials reproduced by eight loudspeaker arrangements (fourteen reproduction conditions) were evaluated by using a Kandoh grading scale. Then, a model to estimate the degree to which Kandoh is emphasized by spatial sound impressions is proposed. The relationship between the degree of Kandoh and the physical properties of the reproduced sound was investigated using multiple regression analysis. As a result, the degree of Kandoh could be estimated from physical properties.