Advocates of the baby monitor say that these systems allow parents to better meet the needs of their children, as they can see or hear everything that's going on even when they're out of the room. Special devices placed beneath the crib mattress can even track body movement to alert parents of any abnormal activity or Sudden Infant Death Syndrome. However, critics claim that even the best baby monitors only provide a false sense of security and have not been scientifically proven to benefit babies or parents. It all boils down to parental preference about whether they want to "spy" on their infants or not.

There are a number of helpful features to look for in a modern baby monitor. For instance, some offer both sound and lights, which is handy for parents who are working, on the phone, or would rather not hear a sudden, ear-piercing shriek through the receiver. Often, the louder the baby cries, the more lights flash. Also, video monitors can show a sleeping baby or a baby who is awake, also eliminating the need for audio tracking. Some wireless baby monitors come with more than one receiver, which is a good option for larger houses or two parents who are on-duty at the same time. Belt clips are ideal for the on-the-go parent who is moving around the house and doesn't want to be bothered with the hand-held receiver. After all, what good is a monitor if one forgets to have it in the room?

One of the primary complaints with the baby monitor is interference. This is the danger with any sort of transmitting device, like a cell phone, cordless phone, pager or wireless internet connection. Cell phones, appliances, radios and fluorescent lights can all possibly interfere with a new baby infant monitor, causing fuzzy reception and strange voices to transmit through the receiver. Even video monitors can suffer poor reception, so it's important that a monitor is selected that operates on different frequencies. (For instance, a 2.4 GHz monitor and a 2.4 GHz cordless phone may interfere). If the next door neighbors are also monitoring a baby, then digital baby monitors will ensure the neighbors aren't listening in to your house.

There are many baby monitor brands to choose from, but here is a quick overview of a few popular purchase options. Consumers like the Evenflo Whisper Connect audio monitor because it offers two channels, a low battery indicator, a belt clip and sound lights, as well as a three-way talk feature so parents can listen, correspond and also talk to baby. The Fisher Price Baby monitor (Sound N' Lights) offers a range of up to 1,500 feet and alerts parents when they're getting out of range. The Graco baby monitor is loaded with features, including multi-child monitoring, 2,000-ft. range, night vision and zoom. Mobi offers unlimited receivers, wide camera angles, voice-activated video transmission and high-resolution screens. Summer has the largest selection of sound and video monitors that are loaded with features like night vision and volume control, although the range isn't as good as other models.