I love submarine movies and the intense feeling when a torpedo is coming with the sonar pinging sound in the background. I decided to see how it worked in Avorion, and personally, I love the result.
1) If you want to try it out, download the WAV file: https://www.dropbox.com/s/jtp60vc83nl8t62/proximity_urgent.wav
2) Then put the WAV file in Steam > SteamApps > common > Avorion > data > sfx > interface
You may want to backup "proximity_urgent.wav" beforehand if you want to revert back to normal.
Let me know what you think!