Here ya go...
;Artificial Intelligence Script
;Header Conjured
desc = Press ENTER for WAV
;Triggers
:state=0:hudreset,hudx=50,hudy=90,hudimagefine=gamecore\text\pressentertouse.tga,hudname=mydisplay,hudhide=1,hudmake=display,state=1
:state=1,plrdistwithin=51:hudshow=mydisplay,state=2
:state=2,plrusingaction=1:hudunshow=mydisplay,state=3
:state=2,plrdistfurther=50:hudunshow=mydisplay,state=1
:state=3:sound=audiobank\user\booster.wav,state=4
:state=4,plrusingaction=0,plrdistfurther=50:state=1
;End of Script
Just use that as the AIMAIN for any Dynamic (Static=No) Entity that you want to be the trigger.
Of course you will need to change the name of the WAV file to match yours.
You should make sure that all audio files/folders are placed in the AUDIOBANK folder.