The Relationship between Target Quality and Interference in Sound Zones

Sound zone systems aim to produce regions within a room where listeners may consume separate audio programs with minimal acoustical interference. Often, there is a trade-off between the acoustic contrast achieved between the zones and the fidelity of the reproduced audio program (the target quality). An open question is whether reducing contrast (i.e., allowing greater interference) can improve target quality. The planarity control sound zoning method can be used to improve spatial reproduction, though at the expense of decreased contrast. Hence, this can be used to investigate the relationship between target quality (which is affected by the spatial presentation) and distraction (which is related to the perceived effect of interference). An experiment was conducted investigating target quality and distraction and examining their relationship with overall quality within sound zones. Sound zones were reproduced using acoustic contrast control, planarity control, and pressure matching applied to a circular loudspeaker array. Overall quality was related to target quality and distraction, each having a similar magnitude of effect; however, the result was dependent upon program combination. The highest mean overall quality was a compromise between distraction and target quality, with energy arriving from up to 15 degrees either side of the target direction.