1. A method comprising: receiving a first voice query from a first user from a first device; converting the first voice query to a corresponding text query; querying a knowledge base based on the text query; receiving a response from the knowledge base that at least partially answers the text query; determining a quality score for the response from the knowledge base that represents a degree to which the response from the knowledge base is determined to answer the text query; determining that the quality score is below a threshold value; sending the text query to a second device, the second device associated with an agent; receiving a response statement from the second device; providing the response statement to the first device; storing the response statement in the knowledge base with the response from the knowledge base; updating the quality score for the response from the knowledge base to increase the degree to which the response is determined to answer the text query in response to storing the response statement in the knowledge base; receiving a second voice query from a second user from a third device; providing the response statement from the knowledge base to the third device responsive to the second voice query; requesting a response rating from the second user of the third device for the response statement provided to the third device; receiving the response rating for the response statement provided to the third device from the second user of the third device; and updating the quality score for the response from the knowledge base with the response rating for the response statement received from the second user of the third device.