When nurse Ryoko is percussing the patient's lungs, a normal percussion note should be heard with a distinct resonance that is flat and dull, with a slight echo that reverberates for a few seconds. The percussion note should be heard louder on the back of the lungs and softer on the front, as the lung tissue is thicker and more compact on the back. Furthermore, it should be heard more distinctly on the left side of the chest, as the right side generally has a thicker chest wall. The percussion note should also be heard louder when the patient is sitting or standing than when lying down.