Phonograph

Phonograph is the first voice recording and reproduction device. Its inventor in 1877 was Thomas Alva Edison.

The rotating cylinder (record) was made of metal, and a helical groove that led the needle was engraved into it. Then a tinfoil was wrapped over this cylinder (the later phonographs used a wax layer instead of the tin). Recording was done through a metallic funnel with the bottom covered by a membrane (originally from a fish gas bladder) that amplified the sound. There was a stylus (needle) connected to the end of the membrane. When recording, the acoustic vibrations of the membrane were transmitted to the stylus and pushed through the tinfoil. During the replay, on the other hand, the needle oscillations were transmitted to the membrane and the vibration generated the sound.