Abstract: A seat with a speaker includes: a support part including a cushion and configured to support a body of a sitter; and a speaker unit configured to output a sound in a first direction which is one direction of out-of-plane directions of the vibrating plate, wherein: the cushion includes an accommodation hole accommodating the speaker unit; and a sound which has been outputted in a second direction opposite to the first direction among the out-of-plane directions of the vibrating plate enters a bottom surface of the accommodation hole and is absorbed in the cushion.

Abstract: A system of optimizing an activation degree of an occupant of a vehicle, the system including: a speaker configured to play music for the occupant; and a controller configured to: determine whether an activation degree detected by an detector is in an appropriate state set in advance; and actuate the speaker to play music when determined that the activation degree of the occupant is not in the appropriate state, the music being selected in advance, being unique to the occupant, arousing pleasant emotion of the occupant, and being high tempo music having a tempo equal to or higher than a predetermined tempo or low tempo music having a tempo equal to or lower than a predetermined tempo.

Abstract: A system of optimizing an activation degree of an occupant of a vehicle, the system including: a speaker configured to play music for the occupant; and a controller configured to: determine whether an activation degree detected by an detector is in an appropriate state set in advance; and actuate the speaker to play music when determined that the activation degree of the occupant is not in the appropriate state, the music being selected in advance, being unique to the occupant, arousing pleasant emotion of the occupant, and being high tempo music having a tempo equal to or higher than a predetermined tempo or low tempo music having a tempo equal to or lower than a predetermined tempo.