An acoustic processing device including a memory storing instructions and a processor that implements the stored instructions to execute a plurality of tasks, the tasks including: an analyzing task that analyzes an input signal; a determining task that determines an acoustic effect to be applied to the input signal, from among a first acoustic effect of virtual surround and a second acoustic effect of virtual surround different from the first acoustic effect, based on a result of the analyzing task; and an acoustic effect applying task that applies the acoustic effect determined by the determining task to the input signal.