John C. Koss, the creator of the stereophone who founded Milwaukee-based Koss Corp., has died. Koss, whose love for music fueled his business, died Tuesday December 21 2021, the company announced in a news release. He was 91. Koss founded the company in 1953 with the initial plan to rent television sets to hospital patients. The consumer electronics company is now best known for its headphones. Koss, with his partner Martin Lange, Jr., developed the first high-fidelity stereophone in 1958. That first stereophone set off the headphone industry. Koss Corp. grew from a family-run mom-and-pop operation to a global, publicly-traded company. Michael J. Koss became president and chief executive officer of teh company in 1991. The Koss family continues to own a large portion of the company's stock, even though the family sold many shares earlier this year when its price soared because of online traders. Koss helped develop industry-standard recording equipment, standardized plugs for headphones and other innovations. Koss grew up in Milwaukee, graduating from Riverside High School. He met his future wife, Nancy L. Koss as a teen. In addition to his son Michael, Mr. Koss is survived by another son, John Jr.; his daughters, Debra Fulton, Linda Moore and Pamela Geimer; 15 grandchildren; 15 great-grandchildren; and his brother, G. Peter Koss. His wife, Nancy (Weeks) Koss, died in 2018. Koss served the community through charity organizations like Junior Achievement of Southeastern Wisconsin. He was a director of the Milwaukee School of Engineering. Contributions from Koss, and his company, to the Medical College of Wisconsin, developed the Koss Hearing and Balance Center and the Koss Cochlear Implant program. There is an endowed chair in Otolaryngology in his name.