Never saw this before...watching while recovering from COvid. The deaf girl in the movie is not mute. She speaks quite well for a deaf girl, who would most likely have impaired speech and language (I'm a speech therapist and worked with students who were deaf and hard of hearing). Also, deafness cannot be cured. Nowadays, there are treatments that can provide some hearing, aids and cochlear implants, but no cures.
The singing, music and romance were wonderful so I put aside my realistic views for all of that!
The singing, music and romance were wonderful so I put aside my realistic views for all of that!