High fidelity or hi-fi reproduction is a term used by home stereo listeners and home audio enthusiasts (audiophiles) to refer to high-quality reproduction of sound or images that are very faithful to the original performance. Ideally, high-fidelity equipment has minimal amounts of noise and distortion and an accurate frequency response as set out in 1973 by the German Deutsches Institut für Normung (DIN) standard DIN 45500. This standard was well intentioned, but only mildly successful in defining 'high-fidelity'. DIN 45 500 approval provided audio equipment buyers with reassurance that their equipment was capable of good quality reproduction. In theory, only stereo equipment that met the standard could bear the words 'hi-fi', but in practice, the term was widely misapplied to audio products that did not remotely approach the DIN basis specifications. By the 1990s, the term hi-fi for expensive high-quality home-audio electronics was largely replaced with high-end audio.