Speech interactive apparatus and computer program product using output prompts and user responses

According to an embodiment, a speech interactive apparatus includes an output unit to output a first prompt; a receiving unit to receive a start instruction of a speech input as a reply to the first prompt; a response control unit to stop the output of the first prompt when the start instruction is received while the first prompt is being output; and a deciding unit to decide on a first determination period, which is used in determining whether a silent state has occurred, based on whether the start instruction is received while the first prompt is being output or based on the timing of receiving the start instruction. When the response is not input during a period starting from the reception of the start instruction till an elapse of the first determination period, the response control unit instructs the output unit to output the first prompt again.