Specialists from NRNU MEPhI have created a laser phonograph for reading old sound recordings from wax cylinders of the late 19th – early 20th centuries. Unlike a conventional phonograph, the device does not touch the medium with a needle and can therefore work even with materials that are too fragile for traditional playback.
Thousands of such cylinders have survived to this day, and some of them have never been played. The recordings include materials from Yasnaya Polyana, folklore expeditions of the 1920s-1930s, as well as the voices of poets and writers. Using a regular metal needle for such media is dangerous: century-old wax can be destroyed.
Instead of mechanical contact, the new system scans the sound track with a semiconductor laser. Special real-time feedback keeps the beam on the track even if it is warped. The device actually reads the surface relief and immediately converts it into sound.
The laser power is selected so as not to heat or damage the wax. Moreover, the beam is deliberately not focused to the limit – this helps reduce the amount of extraneous noise during reading.
The development was named "Divnaya veshch" (Wonderful Thing) – as, according to historical evidence, Anton Rubinstein described Thomas Edison's first phonograph. In the near future, the technology is planned to be tested on a large batch of cylinders, after which systematic digitization and the creation of a publicly accessible collection of historical recordings will begin.