“…To achieve such personal sound zones, the multizone reproduction was firstly formulated as creating a bright zone and a dark zone by maximizing the ratio of energy in the two zones, which is known as the acoustic contrast control method [1,2,3]. Since then, different approaches based on the acoustic contrast control have been proposed, including the pressure matching approach [4,5,6,7], and the modaldomain approach [8,9,10,11]. Besides of creating such two kinds of sound zones (i.e., the bright zone and dark zone), the generation of two zones of silence was investigated in [12].…”