Headphone histoty
Headphones originated from the earpiece, and were the only way to listen to electrical audio signals before amplifiers were developed. The first truly successful set was developed in 1910 by Nathaniel Baldwin, who made them by hand in his kitchen and sold them to the United States Navy. Some very sensitive headphones, such as those manufactured by Brandes around 1919, were commonly used for early radio work. These early headphones used moving iron drivers, either single ended or balanced armature. [...]
