In a mod, find a component which has a field or property of type AudioClip. You should be able to change the value to your own AudioClip

Not possible, unless someone made a mod for it

@KyonIndustries No idea, it's an ancient mod.

@PlaneFlightX Oh wow.
That's very interesting.
My mistake.

@PlaneFlightX is there like a way to add sound like for example gpws or something idk

@TheFlightGuySP There, uh, is a mod which can do this.

@rexzion no I mean like get in the code and change or add audio to the game

you can lower and increase your volume in the settings

@KyonIndustries The music source is probably a script instead of an actual file.
Even if you somehow located the script, attempting to replace it would be tricky, or perhaps just simply not possible without extensive programming knowledge.

That being said, it would be really neat to be able to customize the music of the game. But, I would imagine the reason there's no mod for it yet is simply because the music is an embedded script instead of an actual file. It would be very difficult to make a mod that could modify the music with the way the game works.
Edit: there is, in fact, a mod for this. View PlaneFlightX's comment posted above for a link to the mod.

@TheFlightGuySP yeah I was digging and didn't find anything

Hmm, I have also wondered this.
However, I have never actually found the audio script for the game, and I would imagine it's deeply embedded within the game's code.

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