I don't recall this being discussed here - it's not clear to me exactly why
these discs were not playable - soft wax?


WASHINGTON (AP)  Alexander Graham Bell foresaw many things, including that
people could someday talk over a telephone. Yet the inventor certainly
never could have anticipated that his audio-recording experiments in a
Washington, D.C., lab could be recovered 130 years later and played for a
gathering of scientists, curators and journalists.

"To be or not to be..." a man's voice can be heard saying in one
recordingas it was played on a computer at the Library
of Congress on Tuesday. The speaker from the 1880s recites a portion of
Hamlet's Soliloquy as a green wax disc crackles to life from computer

The early audio recordings  which revealed recitations of Shakespeare,
numbers and other familiar lines  had been packed away and deemed obsolete
at the Smithsonian Institution for more than a century. But new technology
has allowed them to be recovered and played.

The technology reads the sound from tiny grooves with light and a 3D
camera. ...

Many of the recordings are fragile, and until recently it had not been
possible to listen to them without damaging the discs or cylinders.

So far, the sounds of six discs have been successfully recovered through
the process, which creates a high-resolution digital map of the disc or
cylinder. The map is processed to remove scratches and skips, and software
reproduces the audio content to create a standard digital sound file.