Military soldiers now and in WW II using the sound-powered telephone

I bet everyone has found themselves in the precarious situation when your phone dies at the most inconvenient time. Half-way to your destination and forgot your charger? Lost! Chatting with your beau, he’s saying all the right things, the phone dies. Was he about to tell me he loves me! The world will never know.

Sound-powered telephone with handset and earphonesEnter the sound-powered telephone– a clunky device that allows users to talk to each other with the use of a handset and earphones, similar to a conventional telephone, but without the use of external power. For those of you who are like- what’s a conventional telephone—it’s the rectangular corded object secured to your grandmother’s kitchen wall, probably beige, with a long curly cord which attaches the handset to the base. Smaller little square buttons affixed to the larger rectangle are called buttons. You press them in a sequence and if you do it right, someone on the other end will answer. But, enough about that. Back to sound-powered telephones (SPTs)

Most commonly found aboard Naval ships and Coast Guard vessels, SPT’s are not only used on a regular basis but are MANDATORY during ship inspections. Because, while losing power to your cell phone might leave you in a pickle in the outside world, it’s more of a life and death situation in the military and can NEVER be the case on board a ship. In fact, I’d venture to say you could ask anyone who served in the military the question, “What is the one thing you ALWAYS need during an op(eration?) I’d bet the answer would be “comms!” (Short for communications) I couldn’t agree more.

Red sound-powered telephone on the wall

While they are bulky, inconvenient and using technology from the 1940’s… SPT’s ensure you can have stable and reliable comms throughout the ship at any given time. They are affixed to the bulkheads in a few crucial ship spaces- the bridge, engine room, CIC, etc. Then, there are small circular ports scattered throughout the ship to plug-in your portable SPT. I used them a lot during the re-fueling process aboard the ship.

I remember snapping the device around my neck, perching the base upon my chest, wrestling with the forever-tangled black cord, affixing the headphones, then pressing the little silver button on top, like you would a walkie-talkie. But remember there’s no electricity flowing, it is powered by the sound of your voice. Fascinating, right? (Or, I could just be the biggest nerd ever☺)

The microphone transducer converts sound pressure from your voice into an electric current, which is then converted back to sound by a transducer at the receiver nodes. So, if the ship lost power, which happened frequently on my old rust bucket, we could still communicate with one another to ensure we could always fight the ship.

If you find yourself feeling super-jealous you never got to use one, go grab two tin cans, poke a hole in each one and tie them together with a long string. Same concept. Have fun!