DCS sound issues in cockpit

[YellowJacket]

So I've started up DCS and ran into an odd issue;
When I'm in the cockpit view I don't have any engine sounds, gunfire sounds or similar soud effects (for example sonic booms etc.);
I can hear the 'instructor' in the tutorial missions just fine, and the cockpit sounds like the 'over G' warning work perfectly fine too, I just can't hear any sounds that have their source outside of the cockpit it seems.
When I'm in the 3rd person view I can hear all those sounds perfectly.
I've tinkered around a lot with the sound settings, but didn't find a solution to the issue.
I've also checked the game files via the Steam feature.

Does anyone of you guys have the same issue/ does anyone know how to solve that problem?
I haven't really found anything similar in the internet.

[kazereal]

One thing to note is that DCS 1.5 has added "in helmet" audio setting: this means you'll hear things same way pilot would hear (sound insulations and such). Forgetting that and you'll get pretty loud surprises occasionally ;)

Anyway, check if that is enabled, try change it and see what happens.