It would be fairly interesting, to say the least, for a deaf girl to have a boyfriend who's a musician.
In canon, it was fairly touching how, in the end, after everything that happened, Sayaka was simply happy to be able to hear Kyousuke play just once. I wonder how Shizune would take such a situation.
On the other hand, Sayaka and Shizune have some similarities, both having well-intentioned goals, but losing a great deal in their obsessed pursuit of them, including driving away those closest to them to an extent.
Sayaka losing the guy she likes to her best friend is also a little reminiscent of Shizune's boyfriend cheating on her with their mutual friend in her bad ending.