Sounds consists of all the sounds player can hear while playing. Gunshots, ambient sounds, injury, and radio sounds. All these can be modified.
Where are my sounds located
By default, your sound-folder will be located in:
AQ2 PRO: action quake 2/action/sound
How to modify
You can replace any .wav file sound-folder has, with any .wav file with few restrictions:
The .wav file has to be mono
The .wav file has to be max 16bit