Firstly let me say that I'm very glad I didn't see this in the cinema because I found the subtitles being removed a little too soon for me on many occasions. I was glad that I could rewind and even pause the film so I could read what was said.
Most of the dialogue is in sign language. (French Sign Language according to IMDb) When I was very young I had assumed that sign language was international and I wondered why it was not taught to everyone. That would make life much easier for deaf people and solve the language problem for the whole planet! Now that I'm older, I think it was a nice idea.
Anyway, to get back to the film, I also disliked the background sound. Sort of like noises heard underwater. I realize this was intentional, to create an atmosphere of isolation, as was the setting in an old submarine. Nevertheless, the main effect it had on me was to want to turn down the volume.
I was impressed with the young actress, Gaite Jansen, who spent a lot of time walking around a submarine with hardly any clothes on, but seemed not to be bothered by the cold.
Having watched the film, the thing that sticks in my memory is the title. Why 170 Hz?
