Two way Intercom
A two way intercom is used in any place you need two way communication. Some intercoms will allow communication between many different areas whereas others are just between two.
The first decision in choosing the right Two way Intercom is whether you need wired or wireless. Can you easily run wires between the areas where you need communication? While these systems are often lower cost, you need to factor in the cost to purchase the wire and the cost of running the wire if not doing it yourself. With a wired system you usually can only communicate with one other intercom at a time. You can perhaps broadcast a message to multiple intercoms, but when someone responds it will likely be just between a master station and a substation. The substations usually can’t talk to each other either.
With a wireless system, if there are multiple intercoms then they usually all broadcast to each other. You can talk to multiple points at one time, however you may not be able to selectively call an individual intercom with most systems. There are some systems that do have a few channels you can call if you don’t need more than 5 or 6 stations maximum. With some wireless systems you can also get handheld units so you can be mobile and still be in communication with someone.