WASHINGTON, May 2: Nine years after he placed the first telephone call, Alexander Graham Bell tried another experiment: 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.” The flimsy disc was silent for 128 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. (AGENCIES)