I did that last year, but I have to find the script in my huge ofpfolder;
The thrower shouts "fire in the hole", the possible reciever shouts "grenaaaade!!!!"
OK, I've found it. It a old script so maybe things could be done easier and better.
I made a list of all the units who could recieve a grenade. With a trigger WEST/EAST, whatever... present, once, covering the whole map.
Onactivation :
Allunits = thislist
in the init of all throwers :
this addEventHandler ["fired",{_this exec "throwcheck.sqs"}]
throwcheck.sqs
_shooter = _this select 0
_ammotype = _this select 4
?_ammotype == "grenadehand": _shooter say "gren1"
~1
_nade = nearestobject [_shooter,_ammotype]
~0.2
_i = 0
#Lp
_x = allunits select _i
?_x distance _nade < 70 && "man" counttype [_x] > 0 : _x say "gren_r1"
_i= _i + 1
?_i < count allunits : goto "lp"
gren1 and gren_r1 are two custom sounds
I've wrote it for a cutscene and it did the job, I doubt it will work in all situations
Here you go, it's funny to hear my own voice
http://users.telenet.be/blanco/Scripts/DVE.Intro.zip