39. The method of claim 33, wherein at the outputting step, the visual response is outputted at an earlier timing than a timing for outputting the visual response when the speech response is the full speech response.
33. The method of claim 21, wherein at the generating step, the speech response for making a confirmation of the input speech is generated, the speech response being changed from a full speech response to a simplified speech response, according to a length of the speech response for making the confirmation.