[Bill Noble[_2_]]

http://historytogo.utah.gov/salt_lak...rs/070801.html

"In the 1920s, the sleepy Salt Lake County farming community of East Mill
Creek was home to Utah's first high-tech boom. The Baldwin Radio Company
employed 150 men and women around the clock, producing a remarkable
variety
of gadgets, including "Baldy Phones," the first radio headsets. Few
remember
that Nathaniel Baldwin, an eccentric Utahn, invented headphones in 1910.
During the Roaring '20s, his company generated $2 million in yearly
sales,
worth 10 times that amount today."

Koss didn't even innovate the idea of high quality headphones. Radio
headphones underwent a steady increase in quality:

Koss's phones were light, circumaural, comfortable and STEREO. Those were
his
contributions.

a form of stereo headphones was used in WWII and maybe earlier - one radio
channel on one ear, a different channel (or intercom) on the other ear -