Which Japanese emperor announced Japan's World War II surrender in a radio address?

Emperor Hirohito announced Japan’s World War II surrender in a radio address broadcast on August 15, 1945.

The speech is known as the Hirohito surrender broadcast or the Jewel Voice Broadcast. It transmitted the Imperial Rescript on the Termination of the War, in which Hirohito said Japan had accepted the terms of the Allied declaration.

Many Japanese listeners had never heard the emperor’s voice before. The recording used formal Classical Japanese and poor-quality audio, so many people did not immediately understand that Japan had surrendered. The word “surrender” was not stated directly in the speech.

The broadcast followed the atomic bombings of Hiroshima and Nagasaki, the Soviet declaration of war on Japan, and intense debate within Japan’s leadership. A failed military coup attempted to stop the recording from being broadcast, but the speech went out at noon Japan Standard Time.