1. A conversation control apparatus for outputting a response in reply to speech from a user, comprising: a conversation database unit storing a plurality of items of conversation topic specifying information; a conversation control unit for storing a conversation history determined using previous conversations and previous replies and selecting a reply sentence using conversation topic specifying information determined using the conversation history and conversation information; and an environment recognition unit for acquiring environment recognition information, wherein the environment recognition unit generates event information based on acquired environment recognition information, and the conversation control unit selects a reply sentence based on the event information.