Nine years after he placed the first telephone call, Alexander Graham Bell tried another experiment when he recorded his voice on a wax-covered cardboard disc on April 15, 1885, and gave it an audio signature: "Hear my voice - Alexander Graham Bell."

Furthermore, the inadequate disc was silent for 138 years as part of the Smithsonian Museum's collection of early recorded sound, until digital imaging, computer science, a hand-written transcript and a bit of archival detective work confirmed it as the only known recording of Bell's voice.



In fact, Ms Carlene Stephens, curator of the Smithsonian's National Museum of American history, first saw this disc and nearly 400 other audio artifacts donated by Bell when she joined the museum in 1974, but she didn't dare play them then.

As a concluding factor, Ms Stephens said by email that their experimental nature and fragile condition have made them unsuitable for playback.

(AW:Samrat Biswas)