Emperor Hirohito’s recorded 15 August 1945 announcement is commonly called the Jewel Voice Broadcast.
The nickname refers to the unusual fact that many Japanese civilians heard the emperor’s voice publicly for the first time. The recording transmitted the Imperial Rescript on the Termination of the War, in which Hirohito accepted the terms of the Potsdam Declaration and ordered Japan’s armed forces to cease fighting.
The broadcast was made in formal Classical Japanese, and its low audio quality made it difficult for many listeners to understand. It did not use the plain phrase “Japan surrenders,” which is why the announcement is often described through its historical title or nickname.
The broadcast marked Japan’s announced acceptance of surrender, but it was not the formal legal signing that ended the war. That ceremony took place aboard USS Missouri in Tokyo Bay on 2 September 1945.