Approach to Recreating a Sound Field

Abstract

To re-create a “concert hall in a telephone booth,” a smaller volume is delineated within the original environment. The surfaces of this sound-transparent volume are covered with microphones, all having a directional pattern facing outwards from the volume. The sampled space is reproduced with an array of loudspeakers corresponding to the microphones, but with their directional pattern pointed inwards. Since the listeners can move freely within the re-created environment, some basic limitations associated with binaural listening are removed. Experiments were made with a 12-channel system. Studies included (a) effects of sampled-volume size, (b) microphone spacing and distribution, (c) space “magnification,” (d) use of small inexpensive speakers for the multiple channels with fewer large speakers for bass, (e) high-absorption listening environments, (f) effects of a finite number of channels.