Creating properly commented .ogg audio for STALKER is actually very simple. You will need a few tools, though:
Audacity - A free wave editing application (any other wave editor will work fine)
X-Ray SDK v0.7 - most current SDK released for Call of Pripyat; will also work for Clear Sky and Shadow of Chernobyl audio
First, you'll need to record, edit, create, and/or mix your own audio file - which is where Audacity or your wave editor of choice comes into play.
After you're done with editing your file, you'll need to save it into the SDK's rawdata folder (C:\Program Files\X-Ray CoP SDK\editors\rawdata\sounds\). Make sure you wave the file as a mono (1-channel), 16bit, 44.1kHz file. If you're working with Clear Sky or Call of Pripyat, system sounds and music files should be saved as stereo (2-channel). *note* - Shadow of Chernobyl does not support stereo sounds, and will CTD upon attempting to play them.
Once you've saved your file into the rawdata folder, open the SDK Level Editor, then in the menu on the right hand side, select sounds>sound editor.
With the Sound Editor open, you'll notice two primary columns:
One the left-hand side, you'll see the directory tree and files within the rawdata folder. On the right-hand side, you'll see a list of different config settings available:
Quality - this value is used to determine the final compression quality of the converted .ogg
Min Dist - this value sets the minimum distance from the sound's source the player can hear the sound at 100% volume
Max Dist - this value sets the maximum distance from the sound's source the player can hear still the sound being played
Max AI Dist - this value sets the maximum distance from the sound's source that AI can still "hear" the sound
Base Volume - sets the base volume level of the sound (this value will be adjusted dynamically in-game based of different variables)
Game Type - sets the declared type of sound (used by the engine to assign AI recognition, playback priority and volume adjustment levels)
Auto Att - this will "attenuate" the sound by either the current set Max Dist or Min Dist; it literally will set the min/max for the sound to achieve a steady fade-out over distance
Control - used to play/stop the currently selected sound - can only be used if the raw file has been converted to .ogg
Autoplay - will automatically playback the selected file if has already been converted to .ogg
MANAGE - will "synch" all current files without closing the editor
*for the editor to convert your currently selected .wav to .ogg, you MUST make some kind of change to the current values. The easiest way to accomplish this is to simply bump the quality setting a bit.
*the higher your quality setting, the better the final converted file will sound, but the larger the file will be as well. The smaller the quality setting, the poorer the sound, but the smaller the file.
*use the attenuation graph to get an idea of how the sound will fade out, based on your current min/max settings - ideally, you want your sound to fade out properly so that it won't "cut off" as the player moves away from it
*depending on the type of sound, be careful of setting the AI distance too high - this can lead to odd AI behaviour as they'll be able to "hear" the sound much further than would be realisitic
*choose a sound type that most closely matches what type of sound it is - the sound types are used heavily by the game engine for AI recognition. For example, if you set an explosion to world ambient, AI will not react to the sound at all.
*set a base volume on par with the type of sound you're working with. If you set too low or too high of a value, it can affect AI recognition. Using a value of 2.00 is fine for explosions, but not for footsteps (AI would "hear" footsteps even if the player was slowly walking across cloth).
Once you've set your values, hit the "OK" button, and the sound editor will convert and comment the file. Converted files are saved into the SDK's gamedata folder (C:\Program Files\X-Ray CoP SDK\editors\gamedata\sounds\) in .ogg format. From here, they can be copied into your STALKER
More information can be found here:
Further questions can be asked here: