How Intercoms Have Evolved Over Time

How Intercoms Have Evolved Over Time

The intercom technology has been around long before intercoms became common in homes and workplaces. Intercoms were initially built on telephone technology, with the makers soon moving on to more advanced technology.

The apartment intercom system was invented over a century ago. The first ever intercom was essentially a tube that could carry sound for up to 300 feet. Here is an overview of intercom evolution over time.

Speaking Tubes

Multiple versions of the intercom were invented during the 19th century before Kellogg patented it. Engineers created speaking tubes to transfer people's voices within buildings. Some systems were even effective across hundreds of feet.

Speaking tubes operated by transporting vibrations that moved in the form of an acoustic wave via the air in the tubes. The human mind would interpret these vibrations as sounds. Around the 1880s, this technology became sophisticated enough to allow a person to communicate with up to 25 different offices.

Telephone-Based Intercoms

The invention of the telephone by Alexander Graham Bell in 1876 played a major role in intercom evolution. In the early 1900s, telephone-based intercoms became the standard in buildings with multiple families.

By the latter half of the century, speaking tubes were common in workplaces. In 1894, the Kellogg Switchboard and Supply Company patented the first telephone-based intercom. It functioned when a visitor would tug at a handle on a panel installed at the entrance of a building.

This would make an electric current travel via wiring to a receiver inside the apartment. The receiver would emit a buzzing sound to inform the resident about a visitor. While this did not allow the residents to speak to the visitors, it was cheaper than getting tubing installed all over the property.

Apartment Buzzer

Wireless intercoms that used radio frequencies had already been invented by the late 1940s. In the 1950s, apartment buzzers were invented that functioned as electronic doormen. It allowed visitors and residents to speak to each other directly by pressing a button.

This intercom consisted of hardware at both the entrance of the building and the unit's interior. Electronic locks on front doors could be opened remotely through a button on the unit’s hardware. In other words, if a resident decided to let a visitor in, they could simply press a button to do so.

Video Intercoms

After apartment buzzers, the invention of transistors paved the way for further technological advancements in the intercom system. It wasn’t long before video and audio identification methods came into being.

Video intercoms were invented in the 1980s and consisted of a camera and screen. It used to be linked through wiring within the entire building. Visitors would press a button to communicate with a resident, which would start a video camera and display an image on the unit's screen.

Modern Intercoms

Intercom evolution began from the speaking tubes of the 19th century and quickly developed into complex yet user-friendly systems that exist today. There is a wide range of intercoms available in the market, with many allowing you to open doors simply through a smart device.

With these advanced systems, not only can you see your visitor but also video chat with them. Some systems allow you to even send temporary QR codes to visitors that function as virtual keys. Another interesting feature of modern-day intercoms is that you can get time- and date-stamped photos of every visitor.

Intercoms today offer WiFi connectivity, baby monitors, gate entry systems, and one-touch controls to make life easier. They also function as security systems where you can spot and report suspicious visitors in time.

For the most advanced intercoms and other interesting gadgets, check out