Percutaneous endoscopic gastrostomy (PEG): A surgical procedure for placing a feeding tube without having to perform an open laparotomy (operation on the abdomen). The aim of PEG is to feed those who cannot swallow. PEG may be done by a surgeon, gastroenterologist (GI specialist).
While the intensity of a sound is a very objective quantity that can be measured with sensitive instrumentation, the loudness of a sound is more of a subjective response that will vary with a number of factors.
Intensity and Volume. The energy in a sound wave has to travel over a certain area in a certain amount of time. We detect sounds as being louder when we're standing closer to the source and quieter when we're standing further away. The amount of energy we detect is known as the intensity.