Luffy gripped the giant gold ball attached to his arm. He didn't just want to hit Enel; he wanted to ring the bell that had been silent for 400 years.
"Let the old man hear it!" Luffy roared.
Amine stood up, using the last of his energy to draw a 'Signal Booster' in the air. "Luffy, now! I'll make sure the sound reaches every 'Partition' of the sea!" As the gold hit the bell, the sound didn't just ring; it 'Broadcasted'. It shattered the 'Shadow-Filters' above Jaya, letting the world below know that the City of Gold was real.