Intercoms

Shortly after Alexander Graham Bell’s first telephones became well known, people used the principles behind his invention to create basic intercom systems. An intercom is defined as a personal device that permits the exchange of verbal messages between two or more locations, in places where standard communication would be difficult or impossible. But even before the advent of the telephone, there were devices in use that were similar to the modern intercom. They were common in large offices, on ships and in military installations. Residential estates and manor homes also used these gadgets to relay instructions to workers or servants who were out of earshot. More than just a system of ropes and bells, they were called “speaking tubes” and consisted of hollow metal pipes, which conducted sound for long distance. We can observe this phenomena even today when visiting old buildings heated by water pipes that tend to conduct every sound from room to room whether desired or not.

A favorite toy of children constructed by connecting two cups together with a length of string can also be considered a type of intercom, as can the telegraph. Both of these devices form a closed rather than open system of communication. Of course modern intercoms have taken the concept to a whole new height, and the new wireless systems have provided an entirely different level of sophistication.

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