An archival database of high-resolution directivities

Having easily accessible and accurate directivity patterns of sound sources is valuable for many applications, including architectural acoustics modeling and spatial audio. To provide this information to other researchers, the authors of this presentation are creating an online directivity database for live human speech, played musical instruments, and other sources of sound. The results are derived from recordings of the sources over their useful bandwidths at 2522 unique microphone positions over a surrounding sphere (i.e., with 5-deg resolution in both the polar and azimuthal angles). Processing of the recordings has led to frequency-dependent spherical-harmonic expansions. The expansion coefficients, as well as broad-band tabulated attenuation results (commonly used in architectural acoustics simulation packages), are freely available in the ASCII format. The database also contains figures and animations of the directivity patterns, allowing for quick visualization. The collections should help improve modeling of various acoustic spaces, microphone placements for recordings, and general understanding of source radiation characteristics.