When my kids were babies, between 15 and 20 years ago, we went through a fair number of baby monitors. The trouble was, you never really knew until you got them home and tried them out, if they were going to work well or not.
They were prone to interference from a wide variety of different thing - the mains supply, radios, mobile phones (yes, there were mobile phones back then) - even passing taxis and police cars. I think we went through three or four before we found one that worked.
Things are a bit different these days. Even although there are probably more sources of interference around these days, the monitors are much better designed and shielded. They work a lot better - and some of them, most of them in fact, have video monitoring capabilities as well.
You can watch your baby, even in a darkened room. Talk about keeping an eye on them all the time!
Some monitors have two way communications. You can talk to your baby remotely - the sound of your voice might be comforting to them, and they'll certainly know that you're on the way to attend to them.
Check out some of the best night vision baby monitors 2014 below. Some of them look like they belong more in a James Bond movie rather than a nursery!