ääninauha

An ääninauha, often translated as sound tape or audio tape, refers to a magnetic tape used for recording and reproducing sound. This technology was prevalent throughout the 20th century, evolving from early reel-to-reel formats to more compact cassette tapes. The tape itself consists of a thin plastic film coated with a magnetic material, typically iron oxide or chromium dioxide. When sound waves are converted into electrical signals, they are used to magnetize particles on the tape, creating a pattern that represents the original audio.

The process of playback involves passing the magnetized tape over a playback head, which detects the magnetic variations. These variations are then converted back into electrical signals and amplified to reproduce the sound. Different types of ääninauha existed, with varying tape widths, thicknesses, and magnetic properties, influencing recording quality and duration. While largely superseded by digital recording technologies like CDs and digital audio files, ääninauha played a crucial role in the democratization of music, broadcasting, and personal recording, leaving a significant legacy in the history of audio technology.