Many people who work with me got their first contact with a computer in the ADSL age and never even heard a modem handshake. Two people here used cassette tapes for storing programs, I for my Apple II, the other guy with his Sinclair and, later, his MSX. Some time later I wrote a program that dumped a floppy into a cassette tape for backup.

In case you wonder what are you hearing, it's the audio modulation of a memory dump. If you pay close attention, you can distinguish between program (noise-like) strings (less noisy) and graphics (more rhythmic sounds). Try the lo-fi link for maximum vintage feel.