Express Paper
How much can the number of microphones for 3D audio recording be reduced while maintaining spatial impression?
AES Convention 154 · Paper 63 · May 2023
Abstract
Many sound recording methods have been proposed for recording 3D audio. Typically, these methods require at least as many microphones as the number of playback channels. In this study, the authors propose an upmixing method for using fewer microphones. Two methods of upmixing are described, one referring to the MS (mid-side) method and the other generating coherent and diffuse sound components. Using the aforementioned up-mixing technique, the 3-AFC method was used to compare the original 20-channel sound with material converted from 5, 7, and 9 channels to 20 channels. The listening test results showed that the proposed method was perceived as “slightly different” compared to the original 20-channel material unless the material contains a great deal of direct sound in the top layers. Furthermore, from the comments received on the comparison with the original 20 channels, converting a 9-channel or 7-channel signal to 20 channels using the proposed method will result in a higher sense of spaciousness and envelopment.
