Basically there are three types of apnea: obstructive, central and mixed. Obstructive apnea is most common in babies and children. It is caused by obstructions in the airway such as adenoids and enlarged tonsils. This is quite dangerous especially for babies since it usually happens during sleep time. They use a small camera either mounted on the wall, table or crib to transmit the images into the LCD display. They are usually portable and come with multiple cameras and even night vision. Sensory monitorsdetect the baby s slightest movements even during sleep. It fits under the mattress of the baby and alarms you when the baby stops moving or is absolutely still for 20 seconds. When examined by experts, these sounds can t be technically explained. But when examined by professional ghost hunters, they turn out to be ghost voices also known as electronic voice phenomenon. Baby Monitors and Interference Baby monitors can either be wired and wireless. Both types of devices have their own advantages and disadvantages. And the sensory monitor is a movement detector that alarms the parent when it cannot perceive any movement from the child for more than 20 seconds. How Does It Play A Role In the Safety of the Child? What baby monitors basically do, is allow the parents to know their child s activities and to watch out for any possible problems from afar, especially if the baby is asleep. Then again, technological innovations have made it possible to combine sound and visual monitoring. Although the video option seems like a brilliant idea, you still won't be able to stare at the screen all the time. For that reason, you definitely shouldn t sacrifice an excellent sound quality over supplementary features. It is more important when you live in a flat where there are a lot of people and strangers can easily come and go. 2) Just like with any electronic device, do not let your baby monitor, either the transmitter or receiver, get in contact with water. These devices have enough electricity in them to cause shock.