(First Stereo) Headphones

In 1958, John C. Koss, an audiophile and jazz musician from Milwaukee, produced the first stereo headphones.Previously, headphones were used only by the US navy, telephone and radio operators, and individuals in similar industries. Smaller earbud type earpieces, which plugged into the user's ear canal, were first developed for hearing aids. They became widely used with transistor radios, which commercially appeared in 1954 with the introduction of the Regency TR-1.