try this (not sure if it will work)
--client
function startSirene ( vehicle )
local x,y,z = getElementPosition( vehicle )
sound = playSound3D( "sons\\sirene1.wav", x, y, z, true)
attachElements ( sound, vehicle)
end
addEvent( "startSirene", true )
addEventHandler("startSirene", getRootElement(), startSirene)
function stopSirene()
destroyElement(sound)
end
addEvent( "stopSirene", true )
addEventHandler("stopSirene", getRootElement(), stopSirene)
--server
function startSirene( player, cmd )
local commandant = createVehicle ( 554, 1227.746, -1422.281, 13.5432, 0, 0, 0, "COMM1" )
triggerClientEvent ( player, "startSirene", getRootElement(), commandant )
end
addCommandHandler ( "sireneon", startSirene)
function stopSirene( player, cmd )
triggerClientEvent ( player, "stopSirene", getRootElement() )
end
addCommandHandler ( "sireneoff", stopSirene)