The amplitude of a sound refers to the maximum displacement of air particles caused by the sound wave. In general, the amplitude is a measure of the intensity or loudness of a sound. A quiet sound typically has a relatively low amplitude, meaning it causes a small displacement of air particles and is perceived as being softer or less intense. However, it's important to note that the perception of loudness can vary among individuals, and what might be considered quiet to one person could be perceived differently by another. Additionally, the specific numerical value of the amplitude depends on the unit of measurement being used, such as decibels (dB) or pascals (Pa), and can vary depending on the measurement scale and reference point.