Sony Portable Audio in 1991

By 1991, the shift toward compact disc was no longer a question of direction. It had already happened. CD was overtaking cassette globally, and Sony’s role was no longer to balance formats, but to expand what the new dominant format could become.

Inside that shift, portable audio began to branch into multiple paths. Discman models continued to improve, becoming more stable and more practical for everyday use, while cassette Walkman remained present but increasingly defined by refinement rather than change. At the same time, Sony began to explore entirely new applications for portable CD technology, moving beyond music into areas like data and professional audio.

What defines 1991 is not a single dominant product, but the moment when portable audio stopped being a single category. Sony was no longer just building players. It was testing the limits of what portable media could be. That expansion would not always lead to lasting formats, but it marked the beginning of a broader idea of personal audio that extended beyond music alone.