**4. Conclusions**

In this paper, we presented a sound coding color (SCC) design methodology to ascertain whether a person with a visual impairment (PVI) can interact with color through sound without a complex learning process. Although several researchers have done color–sound matchings previously, to the best of our knowledge, no one has experimented with whether PVI can distinguish the color–sound matchings e ffectively. In this paper, a series of user tests was performed on increasingly refined SCCs developed through user feedback. During the test, the user experience evaluation rate from nine blind musicians for the CLASSIC SSC V1 and VIVALDI SCC V1 was 77% and 84%, respectively. The user experience scores from eight sighted participants were 79% and 80% for CLASSIC SCC V2 and VIVLADI SCC V1, respectively. The music composed to convey the color arrangemen<sup>t</sup> of Van Gogh's starry night using CLASSIC SCC V2 received a user experience rating of 83.5%. Finally, after training three congenitally blind adults in both VIVALDI SCC V2 and CLASSIC SCC for about one hour, the recognition rate for both CLASSIC SCC V2 and VIVLADI SCC V2 was 100%. Therefore, the CLASSIC and VIVALDI SCCs helped participants appreciate the overall color harmony of artwork. In [34], in pitch perception, the congenitally visually impaired group was found to be superior to the acquired visually impaired and sighted groups. The "time change analysis ability" of sound was also found to be superior in the congenitally visually impaired group and the acquired visually impaired group than in the sighted group. In [35], early blindness was linked to enhanced perception of the auditory world, including pitch perception. We shall leave extra experiments on more PVI who are not musicians as future work, along with an experiment to find out the di fferences in perception among various levels of visually impaired and sighted people regarding our proposed SCC sets. Additionally, as a future study, we shall explore the simultaneous cognition ability of PVI when dealing with both color–temperature code [36] and the color–sound code presented in this paper.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2079-9292/9/11/1981/s1.

**Author Contributions:** Conceptualization, J.D.C. and J.J.; methodology, J.D.C., J.J., H.L. and J.H.K.; validation, J.D.C., H.L. and J.H.K.; formal analysis, J.D.C.; investigation, J.D.C., J.J. and J.H.K.; resources, J.D.C., J.J. and J.H.K.; data curation, J.D.C., J.J. and J.H.K.; writing—original draft preparation, J.D.C. and J.J.; writing—review and editing, J.D.C.; visualization, J.D.C.; supervision, J.D.C.; project administration and funding acquisition, J.D.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Science Technology and Humanity Converging Research Program of the National Research Foundation of Korea, gran<sup>t</sup> number 2018M3C1B6061353.

**Acknowledgments:** We would like to thank all volunteers for their participation and the reviewers for insights and suggestions.

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