Open‐loop dereverberation of multichannel room impulse responses
We are developing the audio display for a CAVE‐type virtual reality theater, a 3‐m cube with displays covering all six rigid faces. The user’s headgear continuously reports ear positions so headphones would be possible, but we nevertheless prefer loudspeakers because this enhances the sense of total immersion. Because sounds produced at the loudspeakers are distorted by the room impulse responses, we therefore face the problem of controlling the sound at the listener’s two ears. Our proposed solution consists of open‐loop acoustic point control, i.e., dereverberation. The room impulse responses from each loudspeaker to each ear of the listener are inverted using multichannel inversion methods, to create exactly the desired sound field at the listener’s ears. Because the actual room impulse responses cannot be measured in real time (as the listener walks around), instead the impulse responses simulated by the image‐source method is used. A new evaluation criterion is proposed to quantitatively evaluate bot...