[GAMEPLAY] Nexus turret SFX occasionally plays indefinitely after activated

I've noticed this happen on both blue and red side; sometimes when the enemy reaches the nexus turrets and they fire, the SFX remains playing even though it's no longer firing. It does not always happen, I'm not sure about the exact triggers of this bug's occurrence.

1. Let enemy reach nexus turret
2. Let it attack either enemy champion or minion

This bug does not have a 100% chance of occurrence. Exact bug trigger is unclear to me at this point of time.