The first artificial larynx developed by AT&T Bell Labs was purely mechanical. A metallic reed vibrated inside a tube that was connected, by the speaker, between the mouth and the stoma, an artificial opening in the speaker's throat. Air forced up the windpipe, through the tube and across the reed, was then manipulated in the speaker's mouth to create artificial speech.
In 1960, AT&T Bell Labs replaced the mechanical artificial larynx with an electronic version. This required no stoma, and could simply be held against the speaker's throat. A vibrating driver in the larynx replaced the sounds made by vocal cords, which could then be formed into words by the speaker. AT&T made it available at cost worldwide.