THE EFFECT ON SPATIAL IMPRESSION OF THE CONFIGURATION AND DIRECTIVITY OF THREE FRONTAL MICROPHONES USED IN MULTI-CHANNEL STEREOPHONIC RECORDING

摘要

The effect on subjective spatial impression was investigated given variation in the configuration and directivity patterns of three frontal microphones used in multi-channel stereophonic recordings. In particular, this study sought to find an optimal microphone configuration to maintain good sound localization and good spatial impression at off-center listening positions. Two subjective listening experiments were completed in an anechoic room and a low-reverberation room. From the results of the first experiment, involving ratings on combinations of microphone directivity patterns and configurations by comparing "angular distortion", the following microphone array was proposed: a left/right pair of omni-directional microphones spaced at 2m from each other, and a bi-directional microphone positioned 40cm in front of center point between left and right microphones. The second experiment employed the Semantic Differential (SD) method to compare subjective impressions of sounds recorded using two different arrays, one being the proposed configuration and the other being a conventional configuration of three uni-directional microphones. The novel proposed array showed higher "spatial impression" and "softness" scores, and was able to maintain "localization" scores within an acceptable range at a listening position 50cm off the center axis.