I remember the announcement of Pearl Harbor over the radio. I assumed on December 7.
As I recalled it, the president spoke, but that certainly was not the case. It was a news broadcast, at dinner time, probably 5PM E.T. My mom cried, and my dad swore... (he never swore). I was lying under the china cabinet, my hidey place for listening to radio... age five.
In fact, it was not President Roosevelt on the radio, since he didn't announce the attack until the next day, December 8th... when he addressed Congress with the famous "infamy" speech.
What is little noted, was that Eleanor Roosevelt spoke to the nation, in the evening, on the day before... December 7th. A speech that is still taught in journalism school.
For any interest, this site speaks to this, and has pictures of the original draft of that speech with handwritten notes.
December 7, 1941 - FDR: Day by Day