An active acoustic control apparatus includes an alert sound signal generator configured to generate an alert sound signal. An alert sound output device is configured to output an alert sound to an outside of a vehicle. A cancellation sound signal generator is configured to generate a cancellation sound signal representing a cancellation sound to cancel the alert sound, which has been transferred from the outside of the vehicle to an inside of the vehicle, at a sound cancellation target position inside the vehicle. A cancellation sound output device is configured to output the cancellation sound to the sound cancellation target position. The cancellation sound signal generator is configured to detect change of a transfer characteristic from the alert sound output device to the sound cancellation target position and to vary an output characteristic of the cancellation sound depending on the change of the transfer characteristic.