The worst-case scenario flashed through Richard Brown’s mind in 1970, when a doctor informed him that he was going deaf in his left ear.

Then a student at the University of Wisconsin Law School and an aspiring litigator, Brown worried that the diagnosis would derail his fledgling legal career and keep him out of the courtroom. He lost all hearing in his right ear after a childhood bout with the measles, and the prospect of complete deafness was terrifying.