An indicator device (11, 151) includes a plurality of light emitters (L1-L4, R1-R4) and at least one processor (11). The processor (11) obtains, at intervals of a first period (T1), a first period maximum value representing a maximum volume among a plurality of pieces of volume information based on an input signal. The processor (11) obtains, for each second period (T2) including a plurality of first periods (T1) each being the first period (T1), a minimum value among first period maximum values each being the first period maximum value as a second period minimum value and a maximum value among the first period maximum values as a second period maximum value. The processor (11) controls light emission of the light emitters (L1-L4, R1-R4) based on a relative ratio of a predetermined first period maximum value among the first period maximum values. The relative ratio is based on the second period minimum value and the second period maximum value.