卡式录音带
Sony used the Compact Cassette format in many of its tape recorders and players, including the Walkman, the world's first portable music player. Sony introduced the MiniDisc format in 1992 as an alternative to Philips DCC or Digital Compact Cassette and as a successor to the Compact Cassette. Since the introduction of MiniDisc, Sony has attempted to promote its own audio compression technologies under the ATRAC brand, against the more widely used MP3. Until late 2004, Sony's Network Walkman line of digital portable music players did not support the MP3 standard natively.