However, there are also baby monitors that are installed by professionals. Unlike the baby monitors off the shelf, professionally installed ones usually make use of high end gadgets in watching over your baby. The Types of Baby Monitors Basically there are two types of baby monitors: audio and video baby monitors. When this clashing occurs, wireless interference occurs. So to avoid interference, change the frequency of your baby monitor every once in a while and make sure that the frequency you use does not clash with frequencies of other devices. To change frequencies, wireless baby monitors are equipped with a switch that lets parents change frequency easily. More often than not, these portable monitors send out signals between the range of 49,830 MHz and 49,890 MHz. Why do you need to buy one? Mobile baby monitors make it possible for parents to keep tabs on their infants without the necessity of staying awake or standing outside the nursery door all night. Disadvantages of Digital Baby Monitors Digital baby monitors do also have their fair share of disadvantages. One of the most controversial topics about digital technology in baby monitors is health risk. Since these digital devices make use of signals like electro magnetic waves, they may cause health problems to babies especially when they are at that stage when growth and development is on "rapid mode. But on the other hand, manufacturing companies of these digital monitors claim that the amount of radiation that their baby monitors emit are at levels that do not pose serious danger to children. Phillips is one of these manufacturing companies that claim that the level of electro-smog released by their gadgets are 10,000 times lower from the safety norms that are accepted internationally. As a rule, you need to place the radio transmitter within 10 feet of the crib so that it can pick up even the slightest sounds made by your baby such as breathing and movement. You can then carry the portable receiver around during the day or just leave it plugged in at the side of your bed at nighttime.