Decide on a range for the sound to be heard. Create a circle graphic the size of the range of the sound and set it properties to invisible. Give it Fade behavior and set to active on start and destroy after fade out. Don't forget to set or check it's collision properties into the shape of a circle.
Next set sound to play for players when they are on overlap with the circle.
Then set the circle to be spawned from the point of the weapon or explosion or whatever makes the sound.
If another player is close enough, the circle will overlap, the sound will play, the circle will be destroyed. The circle is always invisible.
This the basic mechanic I use to trigger an action to based on range (short range anyway) without calculations. It's easier and more efficient than calculating ranges.
Hope this helps