A notification device for notifying a user through vibration comprising: a plurality of exciters (Ex1, Ex2, Ex3, Ex4) installed in cushion portions of a seat and being located in different positions of the seat; a sweep signal generator configured to generate a sweep signal capable of continuously changing a frequency of a vibration outputted from the exciters (Ex1, Ex2, Ex3, Ex4), by changing a frequency of a predetermined wave at a constant speed in a frequency band which allows the exciters (Ex1, Ex2, Ex3, Ex4) to output a signal causing the user to feel the vibration; a sweep signal divider configured to divide the sweep signal into a higher-band sweep signal that continuously changes the frequency of the vibration by changing the frequency of the predetermined wave in a higher-frequency band which includes an overlap frequency band and whose frequencies are equal to or higher than frequencies in the overlap frequency band, the overlap frequency band being a part of the frequency band in which the frequency of the predetermined wave of the sweep signal is changed at the constant speed, and a lower-band sweep signal that continuously changes the frequency of the vibration by changing the frequency of the predetermined wave in a lower-frequency band which includes the overlap frequency band and whose frequencies are equal to or lower than the frequencies in the overlap frequency band such that the vibration in the overlap frequency band is further emphasized; a signal output determination unit configured to determine that at least one of the higher-band sweep signal and the lower-band sweep signal should be outputted to at least one of the exciters (Ex1, Ex2, Ex3, Ex4) and to determine that at least the other of the higher-band sweep signal and the lower-band sweep signal should be outputted to at least one of the other exciters (Ex1, Ex2, Ex3, Ex4); and an output signal adjuster configured to make an adjustment for outputting the higher-band sweep signal and the lower-band sweep signal to the at least one of the exciters (Ex1, Ex2, Ex3, Ex4) and the at least one of the other exciters (Ex1, Ex2, Ex3, Ex4), determined by the signal output determination unit. a plurality of exciters (Ex1, Ex2, Ex3, Ex4) installed in cushion portions of a seat and being located in different positions of the seat; a sweep signal generator configured to generate a sweep signal capable of continuously changing a frequency of a vibration outputted from the exciters (Ex1, Ex2, Ex3, Ex4), by changing a frequency of a predetermined wave at a constant speed in a frequency band which allows the exciters (Ex1, Ex2, Ex3, Ex4) to output a signal causing the user to feel the vibration; a sweep signal divider configured to divide the sweep signal into a higher-band sweep signal that continuously changes the frequency of the vibration by changing the frequency of the predetermined wave in a higher-frequency band which includes an overlap frequency band and whose frequencies are equal to or higher than frequencies in the overlap frequency band, the overlap frequency band being a part of the frequency band in which the frequency of the predetermined wave of the sweep signal is changed at the constant speed, and a lower-band sweep signal that continuously changes the frequency of the vibration by changing the frequency of the predetermined wave in a lower-frequency band which includes the overlap frequency band and whose frequencies are equal to or lower than the frequencies in the overlap frequency band such that the vibration in the overlap frequency band is further emphasized; a signal output determination unit configured to determine that at least one of the higher-band sweep signal and the lower-band sweep signal should be outputted to at least one of the exciters (Ex1, Ex2, Ex3, Ex4) and to determine that at least the other of the higher-band sweep signal and the lower-band sweep signal should be outputted to at least one of the other exciters (Ex1, Ex2, Ex3, Ex4); and an output signal adjuster configured to make an adjustment for outputting the higher-band sweep signal and the lower-band sweep signal to the at least one of the exciters (Ex1, Ex2, Ex3, Ex4) and the at least one of the other exciters (Ex1, Ex2, Ex3, Ex4), determined by the signal output determination unit.