Direct to Reverberant Ratio Measurements in Small and Midsized Rooms

摘要

The direct to reverberant ratio (DRR) is a critical cue in distance perception studies. In this paper, DRR is measured for three non-idealised rooms of different sizes, using a variety of methods. A combined DRR value for each signal of a binaural room impulse response is presented and compared to the DRR calculated from an omnidirectional room impulse response. Consistent differences were found in the absolute DRR values calculated from each type of impulse, and also when the source is positioned close to a room boundary. While both exhibited the expected trend of a decreasing DRR as a function of source distance, furniture and other reflective surfaces were shown to produce some inconsistencies. The binaural DRR is also shown to vary with source angle, particularly for nearfield sources. DRR values are calculated with a variety of Direct Sound integration window sizes, chosen from previous studies. The results suggest that in smaller rooms, a smaller window size produces more consistent changes in DRR. In addition, a comparison of different source directivities suggests that more consistent DRR values are produced in small rooms when using a directional source, as opposed to an omnidirectional loudspeaker.