C148 Flushing

Simply put, the sound that came out when a Gold Nail was opened was the sound that came out when the Yin Qi inside the coffin was being surged by the Yang Qi.

However, because the hole in a nail was very small, the air would make a "bang" sound when squeezed into a small hole.

Actually, as long as I know that Wu Ji and Zhou Dabao also heard that voice, I wouldn't worry about it in my heart