When 21-year-old Robert Doepgen searches old family archives for a school project, he finds something completely unexpected: details about Adolf Hitler’s voice problems. For more than ten years, Karl Otto von Eiken, Germany’s most famous ENT specialist at the time, treated Hitler’s vocal cords. When Hitler had problems with one of the most important instruments of power in 1935, the Nazi dictator’s voice feared the worst – a serious illness. They appear in old letters recently published, as the Swiss newspaper wrote NZZ on Sunday quoted Reuters . Old letters were once sent from von Eiken to his cousin, and...