Every parent has done it at least once. You thought the baby was awake, you opened the door to peek and — oops, well, the baby’s awake now! It can be difficult to discern a baby’s moans, gurgles and murmurs from outside the door or through a walkie-talkie type monitor, which is why the wireless video baby monitor is becoming so popular. Anyone who has ever used one of the old-school, analog monitors and encountered a sudden, shrill shriek that unpleasantly startled them will no doubt agree that it would …