Emperor Hirohito’s voice was first heard publicly in the 1945 surrender broadcast.
Hirohito recorded the speech on 14 August 1945, and it was broadcast at noon Japan Standard Time on 15 August. The recording announced that Japan had accepted the Allied declaration and would end the war.
It was a historic moment because ordinary Japanese people had never previously heard their emperor speak by radio. The speech used formal classical Japanese, which made parts of it difficult for many listeners to understand.
The broadcast is often called the Jewel Voice Broadcast, but that name should not be confused with the separate formal surrender ceremony on USS Missouri. The broadcast announced acceptance of the terms; the signed instrument later formalized the surrender.