This is the preprint version of our paper on 3rd International Workshop on Virtual and Augmented Assistive Technology (VAAT) at IEEE Virtual Reality 2015 (VR2015). An assistive training tool for rehabilitation of dysphonic patients is designed and developed according to the practical clinical needs. The assistive tool employs a space flight game as the attractive logic part, and microphone arrays as input device, which is getting rid of ambient noise by setting a specific orientation. The therapist can guide the patient to play the game as well as the voice training simultaneously side by side, while not interfere the patient voice. The voice information can be recorded and extracted for evaluating the long-time rehabilitation progress. This paper outlines a design science approach for the development of an initial useful software prototype of such a tool, considering 'Intuitive', 'Entertainment', 'Incentive' as main design factors.