Sound recording and reproductions is a mechanical and electrical writing and re-creation of sound waves, like singing, spoken voice, sound effects or instrumental music. The two major categories of sound recording technology are digital recording and analog recording. Audio analog recording is attained by a minute microphone diaphragm that can sense variations in atmospheric pressure and record them as a graphic presentation of the sound waves on an instrument like a phonograph. In a magnetic tape recording, sound signals vibrate the microphone diaphragm and are changed into a changing electric current, which is then changed to a changing magnetic field by an electromagnet, which builds a presentation of the sound as magnetized fields on a plastic tape. Analog sound re-creation is the converse process, with a larger loudspeaker diaphragm triggering variations to atmospheric pressure to form audio sound signals. Electrically produced sound signals may also be recorded straightly from tools like synthesizer or guitar pickup, devoid of using acoustics in the recording process.
Digital recording and re-creation switches the analog sound wave picked up by the microphone to a digital fashion by the process of digitization. Through this, acoustic data is stored and transferred by a larger diversity of media. Digital recording stores acoustic as a sequence of dual numbers representing samples of the amplitude of the acoustic waves at similar time intervals, at a sample degree lofty enough to communicate all sounds efficient of being heard. Digital recording are believed to be vintage than analog recordings not of the necessity that they have higher fidelity , but due to the digital format that can hinder much loss of quality found in analog recording due to electromagnetic and noise interference in playback, and the mechanical decline to the storage device. A digital acoustic wave must be reconverted to analog form during playback before it is applied to earphones or loudspeaker.