The first time the Japanese people heard their Emperor's voice was when he announced Japan's surrender on the radio during WW2.
On August 15, 1945, Japanese Emperor Hirohito announced the surrender of Japan to his people in the "Jewel Voice Broadcast," or "Gyokuon-hoso." This was the first time an emperor had ever addressed the nation by radio, and Hirohito delivered the speech formal, florid Japanese.
The emperor never used the word "surrender," and continued to justify Japan's earlier aggression, while at the same time advocating for worldwide "prosperity and happiness." He also made reference to "a new and most cruel bomb," cited as a reason for surrender.