How does Recording happen?


 To record sound, the pattern of vibrations in the air must be turned into a form that can be stored. The gramophone was the first sound-recording device. To record, the sound was made to vibrate a needle, which cut a wavy groove in a foil surface. To play back, the needle moved along the groove, making a diaphragm vibrate to reproduce the sound. In the electric gramophone, introduced in the 1920s, the vibrating needle created an electrical signal, which was amplified to drive a loudspeaker.

The first type of gramophone was the phonograph, invented in 1877 by the American inventor Thomas Edison.

Tape recording was developed in the 1940s. To record on to tape, the electrical signal from a microphone is sent to an electromagnet, which creates a pattern in the tiny magnetic particles that coat the tape. This pattern recreates the signal as the tape plays, and the signal is amplified before going to a speaker.

Most sound recording is now done digitally. A microphone turns the sound into an analogue electrical signal, which is then digitized more than 44,000 times a second to create a long string of binary numbers. The binary numbers can be stored in a computer’s memory or disc drives, or on a compact disc (CD). On a CD, the binary digits 0 and 1 are represented by flat areas or shallow pits in the surface. In a CD player, these are detected by a laser as the disc spins and reflected to a light-sensitive device. Electronics rebuild the original electric signal, which is amplified and sent to speakers. Computer CD-ROMs and DVDs work in the same way.

Picture Credit : Google