http://www.lfsforum.net/showthread.php?t=38210

To install put all the sounds in
LFS/Data/Engine/ 

then when in game press (Shift+A)
this will bring up a sound console, 
and go to (Dump Valve Volume)
and click L then type in BOV1
and load it! after you go into 
the console again all 11 Sounds
will be there.