ABSTRACT
Sound recording has taken many forms as technological developments have created new and improved ways of storing information. The first sound recording used smoked paper and a stylus to record sound, but no way of playing back the sound existed until recently. The earliest practical attempts to capture and reproduce sound used mechanical methods, such as Edison’s machines, which connected a large horn to a tiny stylus that traced grooves in a rotating cylinder. Optical systems have long been used for film sound, but analog optical systems are complicated to record and tend to be noisy. The most flexible system of sound recording has been the magnetic approach, in which the sound is converted first to an electrical analog and then to a proportional magnetic flux that leaves a pattern of magnetization on a medium that can retain the signal for a long time.
