Another device with a receiver and with speakers can be carried by you, the parents, or the baby sitter, or anyone who is taking care of the babies. With baby monitors, you can keep track of your baby s even if you are doing something else in the proximity of your house. Types of Baby Monitors Baby monitors have evolved through the years. These added features alert the deaf parent every time the baby is in need of attention. A number of products on the market also offer other means of alerting deaf parents to the cries of their infants. One particular product consists of receivers that come in two parts: a main clock and a tiny sound sensor. A baby monitor is a gadget set that has a transmitter and receiver, which sends either sound or video (depending on the type) for the parent to be able to supervise the activities of the baby while he or she is away. There are different types of these monitors the audio, video or sensory. The audio baby monitor receives and sends sound so that the parent could hear the baby from a distance. Through this, mothers are able to do what must be done around the house thereby accomplishing a lot. From the time baby monitors have been first released, countless of innovations have been made. A variety of products not only permits auditory signals to be heard but even allow the mother from the receiver s end to visualize their baby and play music to soothe the baby even from a distance. If it would be used in a bigger house, then a wider range is required. A smaller house or apartment might not need as much range especially if one lives in an area where there may be a lot of interference such as cell phones and other monitors that could disrupt the signals. But it is also important to consider the user s activity, especially if work might require him or her to be of farther distance from the child. Instead, they receive muffled, indefinable, and sometimes almost inaudible sounds which resemble voices and words coming from a human. 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.