"Woosh" sound at game start

[axxchor]

This is a bit off the wall...(and not really important, either)...but whenever I enter a campaign game (enter the sub, not the office screen) I hear a strange "woosh" sound. It doesn't particularly sound like anything that might actually occur on-board a submarine -- almost like something from a sci-fi movie.

Can anyone tell me what this sound is? Is it something everyone hears? Is it some strange sound artifact? Is it Frenssen farting?

I am running GWX3.0 - although I may have heard the sound before I installed it - can't quite remember.

Cheers for obliging my strange forum questions.

-axx