An active noise control system that is configured to reduce noise, the active noise control system comprising: a first microphone (16, 26) that is disposed in a position displaced in a first direction relative to a user; a second microphone (17, 27) that is disposed in a position displaced in a second direction relative to the user; a first speaker (12, 22) configured to emit sound toward an area around the position where the first microphone is disposed; a second speaker (13, 23) configured to emit sound toward an area around the position where the second microphone is disposed; an error signal generator (18, 28) configured to generate an addition signal by adding an output (LM_L) of the first microphone (16, 26) and an output (LM_R) of the second microphone (17, 27); an adaptive filter configured to perform an adaptive operation of minimizing an error using a signal correlated with a noise as a reference signal and the addition signal as the error so as to generate a noise canceling sound to be output to the first and second speakers; and characterized in that the system comprises a gain adjustment section (184, 186) configured to adjust a ratio between a loudness level of a first noise canceling sound (LC_L) which is the noise canceling sound to be output to the first speaker and a loudness level of a second noise canceling sound (LC_R) which is the noise canceling sound to be output to the second speaker, wherein the gain adjustment section (184, 186) performs the adjustment such that the ratio of the loudness level of the second noise canceling sound (LC_R) to the loudness level of the first noise canceling sound (LC_L) matches a ratio of a loudness level (M_R) of noise transmitted from a noise source (22, 23) of the noise to the second microphone to a loudness level (M_L) of noise transmitted from the noise source (22, 23) of the noise to the first microphone. a first microphone (16, 26) that is disposed in a position displaced in a first direction relative to a user; a second microphone (17, 27) that is disposed in a position displaced in a second direction relative to the user; a first speaker (12, 22) configured to emit sound toward an area around the position where the first microphone is disposed; a second speaker (13, 23) configured to emit sound toward an area around the position where the second microphone is disposed; an error signal generator (18, 28) configured to generate an addition signal by adding an output (LM_L) of the first microphone (16, 26) and an output (LM_R) of the second microphone (17, 27); an adaptive filter configured to perform an adaptive operation of minimizing an error using a signal correlated with a noise as a reference signal and the addition signal as the error so as to generate a noise canceling sound to be output to the first and second speakers; and characterized in that the system comprises a gain adjustment section (184, 186) configured to adjust a ratio between a loudness level of a first noise canceling sound (LC_L) which is the noise canceling sound to be output to the first speaker and a loudness level of a second noise canceling sound (LC_R) which is the noise canceling sound to be output to the second speaker, wherein the gain adjustment section (184, 186) performs the adjustment such that the ratio of the loudness level of the second noise canceling sound (LC_R) to the loudness level of the first noise canceling sound (LC_L) matches a ratio of a loudness level (M_R) of noise transmitted from a noise source (22, 23) of the noise to the second microphone to a loudness level (M_L) of noise transmitted from the noise source (22, 23) of the noise to the first microphone.