Baby Monitor
Before the days of the baby monitor parents had to constantly
walk into the other room to check on their babies. Now, baby monitors
allow sounds and images to be transmitted from the baby's room to the
parents' remote location. This makes life much more convenient: a baby
can be peacefully sleeping and a parent can be watching TV or read a
book while monitoring the infant.
There are two basic types of baby monitors. One baby monitor only transmits
sound. These monitors commonly use an FM frequency to relay noise.
A more expensive baby monitor transmits noise as well as picture. These
can cost as much as $300 and have multiple video monitors for different
rooms. Newer models even have digital picture quality.