Sound recording and reproduction explained to kids

Sound recording and reproduction is an electrical or mechanical inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording. Acoustic recording was the earliest form of sound recording. The first device used to record sound was the phonautograph, invented by Édouard-Léon Scott de Martinville in 1857. It used a vibrating diaphragm to create a stylus tracing of sound waves in smoke-blackened paper. The first practical sound recording and reproduction system was invented by Thomas Edison in 1877. His phonograph used a rotating cylinder with a stylus to record sound on a tinfoil sheet wrapped around it. Edison's major innovation was the creation of the wax cylinder, in which a thin sheet of wax was coated with metal and used as the recording medium. The invention of the gramophone record by Emile Berliner in 1887 allowed sound to be recorded and reproduced on a flat disc with a spiral groove running from the periphery to the center. This was a major improvement over the earlier cylinder format, which was difficult to store and transport. The first commercially successful sound recording and reproduction system was the Victrola, introduced by the Victor Talking Machine Company in 1906. The Victrola was a spring-wound phonograph that used discs instead of cylinders. The introduction of the magnetic tape recorder by Audio Fidelity in 1948 revolutionized the sound recording industry. Tape recording allowed sound to be recorded and reproduced with much higher fidelity than was possible with disc recordings. Digital recording and reproduction converts the analog sound wave into a digital format, which can be stored on a computer or other digital storage devices. The first digital audio recording was made by the German engineer Hans-Joachim Zwicker in 1948. The digital audio format used by Zwicker was based on the Pulse-code modulation (PCM) system developed by Alec Reeves in 1937. Digital audio recording and reproduction has many advantages over analog recording. Digital audio can be easily edited and manipulated using computer software, which is impossible with analog recordings. Digital recordings are also immune to the effects of degradation, which can occur with analog recordings over time.