"When Sony released the first Walkman in 1979, it came with an interesting feature: two headphone jacks. The designers believed that listening to music in public could be seen as antisocial or rude, so they included the second jack to encourage sharing the experience with a friend. Along with this, the Walkman came with a “hotline” button, which temporarily lowered the volume so users could talk without removing their headphones. However, the feature of two headphone jacks wasn’t widely used as Sony expected. People preferred the personal, solitary experience the Walkman provided, which was its main appeal. As a result, later models removed the second headphone jack, focusing instead on enhancing the user’s individual listening experience. This change marked a shift in how people interacted with portable music, embracing the Walkman as a personal device."