The advertising on this movie is quite deceptive, as are just about all the movie reviews.
They discuss the plot, which is touchingly irrelevant to the subject of the movie. Nonetheless, here's the trailer
This movie is about music, and sound, and how to listen for, and to, them both. It is lovely, complex, challenging, and well-crafted. This is the kind of movie to take your kids to, knowing that they will be distracted by the plot, but just to expose them to the process of listening to music.