Experiência pública

Phonograph

The phonograph, invented by Thomas Alva Edison in 1877, was the first device capable of recording and reproducing sound. It featured a rotating metal cylinder with a helical groove that guided a needle. Initially, the cylinder was wrapped in tinfoil, later replaced by a wax layer in subsequent models. Sound was recorded via a metallic funnel topped with a membrane, originally made from a fish gas bladder, which amplified the sound. A stylus attached to the membrane captured acoustic vibrations, etching them into the tinfoil. During playback, the needle’s oscillations were transmitted back to the membrane, recreating the sound.