What was Emperor Hirohito's 15 August 1945 radio surrender announcement called?

Emperor Hirohito's 15 August 1945 radio surrender announcement was called Gyokuon-hōsō. The Japanese term is commonly translated as the “Jewel Voice Broadcast,” referring to the emperor's unusually direct address to the Japanese public.

The broadcast announced that Japan had accepted the terms of the Potsdam Declaration. Hirohito recorded the speech on 14 August, and it was transmitted at noon Japan Standard Time on 15 August. For most listeners, it was the first time they had heard the emperor's voice.

The language was formal and indirect. Hirohito referred to the war situation and the use of a new and cruel bomb, but did not plainly say “surrender” in the modern conversational sense. Many listeners struggled to understand the courtly vocabulary and recording quality, yet the announcement clearly indicated that Japan would stop fighting.

Gyokuon-hōsō is not the same event as the formal signing aboard USS Missouri. The broadcast communicated the decision to the Japanese people; the written surrender ceremony on 2 September completed the legal and military process.