Thomas grip said the music in the game is inspired by silent hill, where the ambient tracks aren't very much music as opposed to something atmospheric to immerse you in the world. I can't find the exact interview where this was mentioned but I believe it was recent.
edit:
nvm, this is the article
http://thewayfaringdreamer.com/the-wonde...d-of-soma/
"In terms of music, Grip provides a relevant anecdote: “I remember reading a review of the first Silent Hill, and the reviewer says, ‘There’s not a lot of music in Silent Hill 1, it’s mostly background noise.’ When I play the game, there’s music all of the time! The music makes the game. There’s tons of music all the time, but he didn’t perceive it that way, this reviewer. It just became part of the experience, whereas if you’re playing Mega Man, its music is obvious. There’s a track playing, it’s very easy to separate that track from the game.”
“In SOMA, the music is more to emphasize what is happening. Initially, we didn’t have a lot of music, because we thought that it would be more realistic that way. What we did, was that a certain area would have a certain ambient tune, and we just let that ambient tune be, regardless of whether or not there was an enemy encounter.”
“Jens began to question this, and as we added more music, we realized it made a world of difference. The music subliminally tells you, ‘Now is the time to be scared.’ If this is done correctly, and works, as it did in Silent Hill 1, the player will not notice on a high level. It’s not explicitly telling you, ‘All clear, no monsters near,’ or ‘Monster is coming, be afraid.’ What it does is build feeling, build tension, and keeps the flow up.”"