A content output device includes at least one processor and at least one communicator. The at least one communicator is configured to output a plurality of channels from the at least one processor to a plurality of audio devices signals. When the number of audio devices increases and at least one additional channel is available to be reproduced, the assigning task assigns the at least one additional channel to the increased number of audio devices and the outputting task outputs the at least one additional channel in accordance with the changed assignment of the plurality of channels.