Effects of room size and reverberation, receiver location, and source rotation on acoustical metrics related to source localization

This study investigates the effects of room size, reverberation, source rotation, and receiver position on two acoustical metrics related to source localization: distortion of frequency-smoothed magnitude (DFSM)and interaural level differences (ILD), as calculated from measured binaural room impulse responses (BRIR). The spaces tested include a conference room, classroom, theater, and concert hall, with mid-frequency reverberation times ranging from 0.4 to 2.6 sec. For all of the BRIRs, a directional loudspeaker source was placed approximately 0.5 m in front of the receiver, simulating a typical conversation distance. In each space, the receiver was located near the center, one meter away from a side wall, and one meter away from the back wall for the measurements. In each location, measurements were made for three different source rotations: 0 degrees, 45 degrees, and 90 degrees from the receiver. The receiver was facing directly toward the source in each condition. The outcomes of this study indicate that at this source-receiver distance, both DFSM and ILD are more impacted by source orientation relative to the receiver than reverberation time. Also, the values are influenced more consistently by the location of nearby reflective surfaces than varying room reverberation.