Board Thread:General Discussion/@comment-71.232.131.59-20131205143653/@comment-174.53.209.153-20200315071419
From Katawa Shoujo Wiki
I can see how you might've misinterpreted that. In the introductions, Shizune was introduced as being deaf AND mute. Misha is neither, and is there to translate for Shizune and those around her. In conclusion, Misha can hear and speak, while Shizune cannot.