One could argue that the first stereo playback system was presented at the Paris Expo of 1881. The Théâtrophone was a system that allowed to listen to live opera and theatre performances over two telephone lines to create a sense of presence.
Théâtrophone was capable of delivering stereo-like sound, although it didn’t technically use modern stereo technology. The Théâtrophone used separate telephone lines and receivers for each ear to create a stereo-like effect, while binaural stereo, developed in the 1930s by an English engineer Alan Dower Blumlein, involves playing two different channels from two microphones picking up sound from different perspectives.
The recording technique that involves placing two microphones crossed at a 90-degree angle from each other is known as the Blunlein Pair, developed by the same engineer. While “stereo” refers to the playback aspect, the “Blumlein Pair” describes the recording technique which creates a sense of depth and precise stereo imaging (which the French didn’t quite achieve earlier).
Stereo broadcasting on radio began in the late 1950s and early 1960s, helping the audience get used to the idea of using stereo as a standard. It was around that time when the sonic “arms race” occurred in the audio industry. During this time, manufacturers competed to develop and introduce new technologies, such as stereo sound, high-fidelity amplifiers, speakers, turntables, and other audio equipment. It took special effort for the companies to convince mono-playback audio system owners to switch to stereo systems. The marketing involved demonstrations, video-visualisations and generally advertising stereo systems as luxurious and advanced (futuristic almost) technology.
Nowadays, stereo is a standard format for audio playback. With immersive audio, virtual reality and a strong community of audiophiles, engineers keep developing stereo and testing its limits. However, the principle invented by Blumlein is still used as a baseline for the stereo we have today.
References:
Borgerson, Janet, and Jonathan Schroeder. “How Stereo Was First Sold to a Skeptical Public.” The Conversation, 12 Dec. 2018, theconversation.com/how-stereo-was-first-sold-to-a-skeptical-public-103668. Accessed 30 Mar. 2024.
EMI Archive Trust. “Alan Blumlein and the Invention of Stereo | EMI Archive Trust.” Emiarchivetrust.org, 2019, www.emiarchivetrust.org/alan-blumlein-and-the-invention-of-stereo/. Accessed 30 Mar. 2024.
“Victorian Era Theatrophone Live Streamed Opera Performances and News.” Racing Nellie Bly, 9 July 2017, racingnelliebly.com/weirdscience/victorian-theatrophone-live-streamed-opera/. Accessed 30 Mar. 2024.