William Parker was a young adult who lived in the Metropolis ghetto. After graduating from college, Parker returned home, where he tried to create a boys' club, but he couldn't get the respect of the kids in the same was as the crooks about town did. Inspired by Superman and Batman, Parker used his engineering knowledge and created sound devices that would help him become the hero called Sonik. On his first attempt to find criminal actitities, he came across Batman and Superman and they stopped a large criminal organization, which earned Parker the respect and admiration of the kids in town. After revealing his identity to the kids, Parker's club started to work and it was improved thanks to Bruce Wayne's funding and Clark Kent's reports, which gave the place exposure.
- This version of William Parker (Earth-One), including all history and corresponding appearances, was initially erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. However the ending of Convergence retroactively prevented that collapse, saving all the alternate realities, though in an "evolved" form. Even though versions of the character may have since appeared, this information does not apply to those versions.
- 2 Appearances of William Parker (Earth-One)
- 1 Images featuring William Parker (Earth-One)
- Quotations by or about William Parker (Earth-One)
- Character Gallery: William Parker (Earth-One)