An acoustic device includes: a memory; and a processor coupled to the memory. The processor executes a process including: first determining, based on a state of a user, an arbitrary object from among objects around the user as an object that is watched by the user; second determining the watched object as a target when a predetermined determination time elapses from a timing at which the arbitrary object is determined as the watched object; generating, when the watched object is determined as the target, acoustic signals for outputting audio of a sound generator corresponding to the target in association with a position of the target; and making, based on a difference between a moving direction of the user and a direction of a body of the user, an adjustment to reduce remaining time until when the predetermined determination time elapses.