The present invention relates to a voice output apparatus capable of, in response to a particular stimulus, stopping outputting a voice and outputting a reaction. The voice output apparatus is capable of outputting a voice in a natural manner. A rule-based synthesizer 24 produces a synthesized voice and outputs it. For example, when a synthesized voice "Where is an exit" was produced and outputting of the synthesized voice data has proceeded until "Where is an e" has been output, if a user taps a robot, then a reaction generator 30 determines, by referring to a reaction database 31, that a reaction voice "Ouch!" should be output in response to being tapped. The reaction generator 30 then controls an output controller 27 so as to stop outputting the synthesized voice "Where is an exit?" and output the reaction voice "Ouch!". Thereafter, the reaction generator 30 controls the read pointer of a buffer 26 controlled by the read controller 29 such that the outputting of the synthesized voice is resumed from the point at which the outputting was stopped. Thus, the synthesized voice "Where is an e, Ouch!, xit?" is output.