In that 1983 comic, Hawkeye lost his hearing after battling Crossfire, who was trying to manipulate Hawkeye and Mockingbird with a machine known as Undertaker.
DiMarco is referring to a 1983 comic arc that started with Hawkeye #4 by Mark Gruenwald, when Hawkeye lost his hearing during a battle with Crossfire.
Shortly after Avengers: Infinity War came out, DiMarco responded to a Mic article about Marvel’s challenges with diversity, stating that “Disability is also a part of diversity, @mic.
I think it would have made [better movies]… if they brought a deaf person in to play a deaf Hawkeye.