Patent attributes
A voice interaction system performs a voice interaction with a user. The voice interaction system includes: ask-again detection means for detecting ask-again by the user; response-sentence generation means for generating, when the ask-again has been detected by the ask-again detection means, a response sentence for the ask-again in response to the ask-again based on a response sentence responding to the user before the ask-again; and storage means for storing a history of the voice interaction with the user. The response-sentence generation means generates, when the response sentence includes a word whose frequency of appearance in the history of the voice interaction in the storage means is equal to or smaller than a first predetermined value, a response sentence for the ask-again formed of only this word or a response sentence for the ask-again in which this word is emphasized in the response sentence.