-- server side:
addEvent ( "onPostFinish", true )
addEventHandler ( "onPostFinish", root,
function ( )
triggerClientEvent ( root, "playSound", root )
end
)
-- client side:
addEvent ( "playSound", true )
addEventHandler ( "playSound", root,
function ( )
playSound ( "url or path here" )
end
)
Not tested, I leave that part to you.