I just saw this a few minutes ago- like their headphones or not, he did change the way music is listened to.
My dad and John Sr met at Boy's Tech high school. They had remained in contact after school and when he was about to introduce one of his new models (early-'60s, IIRC) after the die-cut foam earpads, he had my dad (who was an upholsterer) make the covers for enough sets to take to the big audio show in either Chicago or New York. Our families spent a good amount of time together over the years, too- I was in 1st Grade with John Jr, my older brother was in the same class as Michael, who has been the company President since their dad stepped back. We were also in the YMCA Indian Guides together and the group would be hosted by each family throughout the year. The first time we went to their house, all of the kids were going nuts, not paying attention and generally, being a huge nuisance. John Sr went into a closet, brought out enough headphones for each of us and plugged them in. He had his wife bring out a cart with a bowl of ice cream for each kid and as that came out, he started to play the film reel for Fantasia. As soon as it began, all anyone would have seen was 20 kids with their mouths wide open.
RIP, John Koss