Active noise control system and method for controlling an acoustic noise generated by a noise source at a listening location, in which system and method sound is picked up in the surroundings of the listening location by a sound sensor; an electrical noise signal which corresponds to the acoustic noise of the noise source is generated and filtered adaptively in accordance with control signals. The host device includes a host device application execution unit configured to execute host device applications as applications for host devices and an automatic install unit. The plurality of openings are formed within the bottom, front, and back faces of the housing. The controller controls an ignition timing on the basis of a result of the determination.