**6. Conclusions**

We proposed an auditory card game system that presents the card's contents by sound, towards playing equally with others, regardless of whether they have a visual impairment or not. This is one of the solutions that presents public information of board games. Although this proposal cannot improve the accessibility of all board games, it contributes to expand the range of inclusive board games for the visually impaired. Furthermore, clarifying the impact of element of the system to the players will greatly assist in designing an appropriate board game using the proposed system. The purpose of this paper is to determine whether the game allows for fair competition for people with visual impairments and to clarify the effects of the valuable parameters of the system on the players. In the system evaluation, we developed "Auditory *Uta-Karuta*" and verified the usefulness of this system by having the game played by visually impaired people, sighted people, and sighted people with a blindfold. The purpose of this experiment is to test the applicability of auditory card game system to board games. We found that "Auditory *Uta-Karuta*" has the potential to be played by all players, regardless of whether they have a visual impairment or not. The following experiment was conducted to measure the effect of the design of the audio cue on the player in the proposed system, and several major considerations were obtained.


These results show that it is necessary to design audio cues appropriately due to the characteristic of public information indicated by the components in order to make the auditory card game system effective. In particular, for a board game that requires accurate information presentation for players, such as *Uta-Karuta*, it is considered that playing representational sounds one by one is effective. However, in Section 4, despite the game design described above, the sighted players had an advantage, so it would be effective to adopt a vertical layout that gives an advantage to the visually impaired.

As described above, the results of the experiments in Section 5 can be used to create an appropriate board game design that allows players with different visual states to achieve the same level of game performance. However, the enjoyment of a game depends not only on the winning rate, but also on factors such as strategy and communication. Therefore, further experiments will be needed to construct a board game that is fun for players regardless of whether they have visually impaired or not, with a view to the qualitative factors that may influence the enjoyment of the game. In addition, as mentioned in Section 5.6, the results of this study can even be used for games in which private information is used, and we will

consider applying them to the case of games that include private information in future research. Furthermore, in order to reduce the cost and broaden the range of board games that can be supported, it is necessary to consider not only the iPod touch, but also many other component shapes and types.

**Author Contributions:** Methodology, H.M., N.K., and K.Z.; software, H.M.; investigation, H.M., N.K., and H.E.B.S.; writing—original draft preparation, H.M.; writing—review and editing, N.K., H.E.B.S., and K.Z.; supervision, K.Z.; project administration, K.Z. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by Ethics Review Committee of the University of Faculty of Engineering, Information and Systems, University of Tsukuba (2019R314, 24 May 2019).

**Informed Consent Statement:** Informed consent was obtained from all participants in the study.

**Conflicts of Interest:** The authors declare no conflict of interest.
