3dsound... I think... half works. But there is an easier way.
I know you can set 'sound intensity' or 'volume' with scripts... just not certain of the command but... (perhaps the soundscale command?)
simply doing
:plrdistwithin=100:sound=$1,soundscale=25
:plrdistwithin=75:sound=$1,soundscale=50
:plrdistwithin=50:sound=$1,soundscale=75
:plrdistwithin=25:sound=$1,soundscale=100
(unless I am wrong on the usage of 'soundscale')
Your mod was deleted by the government.
http://forum.thegamecreators.com/xt/xt_apollo_pic.php?i=811392