Transistor radio
A transistor radio is a small portable radio receiver that uses transistor-based circuitry. Following their development in 1954, made possible by the invention of the transistor in 1947, they became the most popular electronic communication device in history, with billions manufactured during the 1960s and 1970s. Their pocket size sparked a change in popular music listening habits, allowing people to listen to music anywhere they went. Beginning in the 1980s, however, cheap AM transistor radios were superseded by devices with higher audio quality such as portable CD players, personal audio players, boomboxes, and (eventually) smartphones, some of which contain radios themselves.
Regency TR-1
In May 1954, Texas Instruments had designed and built a prototype transistor radio and was looking for an established radio manufacturer to develop and market a radio using their transistors. No major radio maker, including RCA, Philco, and Emerson, was interested. The President of I.D.E.A. at the time, Ed Tudor, jumped at the opportunity to manufacture the TR-1, predicting sales of the transistor radios would be "20 million radios in three years." The Regency Division of I.D.E.A announced the TR-1 on October 18, 1954, and put it on sale in November 1954. It was the first practical transistor radio made in significant numbers.