This easter egg can be found on the map, Favela which released as part of Operation Skull Rain.
Located on the west side of the map Favela, players will find a concrete soccer field with numerous soccer balls in the area as well as two goals.
Using either a drone or your gun, if you push any of the soccer balls into either one of the goals you will hear an announcer yell, “GOAL!” over a loudspeaker. However, depending on which goal you score in the sound effect may be close or further away, with the southern goal giving off the loudest sound.
This easter egg can also be done an unlimited amount of times, and as long as no ball is in the goal, you can initiate the sound effect by scoring from anywhere outside of the goal line.