(3) If you discover any such places, use the right middle finger to press on the spot, using the left middle finger to hit the third knuckle of right middle finger. Listen, comparing the sound to what's made elsewhere. If it has a more drum-like quality, then there is flatulence here.
③如有發現，便用右手中指按住此點，再拿出左手以中指敲打右手中指第二指節，聽發出的聲音，並比較與他處是否不同，如果像鼓聲，就表示此處有「脹氣」。