Kirk Langstrom a hard working scientist who works for Hugo Strange. He has made a break through in coming up with a cure for deafness. But Hugo strange saw that the formula could be use for the military as a weapon to get intel from targets. With learning what Strange was up to Kurt takes his untested formula and injects himself with it because is partially deaf. At first it works but then he starts to change into a bat like creature that frames Batman for crimes he did not commit. 

Take inspiration from Robin Atkin Downes, Xander Berkeley, or Phil Lamarr's interpretations of Man-Bat/ Kirk Langstrom.