Synthesis of Moving Reverberation Using Active Acoustics—Preliminary Report

An ambient sound field created artificially using active acoustics (virtual acoustics) attempts to resurrect the perceived naturalness of the original architectural space and the distinct responsiveness to musical sound sources. Moving reverberation is typically associated with coupled volumes contained within a larger architectural space, where each volume is activated by a sound source at a different moment in time due to propagation delay. The produced energy has a diverse characteristic rate of decay with which its energy is mixed within the common space causing multiple slopes on the decay. This causes a sensation of a decaying diffused sound that is not homogenized but distinctly appearing in different zones of the space as a shifting acoustic energy. In order to reconstruct the moving reverberation, an active acoustics system was used to render an ambient sound field from measured impulse responses of large architectural space, the Grace Cathedral in San Francisco.