Wyzant marked this one as answered, but when I clicked on it, the display showed no answers, so I decided to chime in on this one. As it happens, I have studied Pearl Harbor as a hobby for quite some time now. Part of your question was cut off, but I will answer what I can.
Cellphone technology did not exist back then and even landlines were not universal, so information moved more awkwardly than it does now. However, the telegraph had been in existence for quite some time and was, in its own way, the internet of that era. People not only received information, but could -- if they had the money -- privately transmit it as well. However, this mainly offered targeted transmissions. You couldn't broadcast it widely. I recommend the fascinating book The Victorian Internet by Tom Standage for more on the topic.
Television barely existed at the time, with competing technologies fighting to dominate the field. With so many of our resources already tiptoeing into the upcoming conflict, we could spare neither the manpower nor the materials to focus on improving it much. For this, I suggest the definitive guidebook on this, Tube by David and Marshall Fisher.
So: how did they learn about it? Radio existed, of course, as well as newspapers, but each of them had to learn about it first, which meant either the telegraph or a reporter calling in from the area. Even then, newspapers took a while to verify facts, write the stories, and finally print / deliver the finished paper. Some people might have heard about the attack this way, but most likely heard about from FDR's "infamy" speech announcing the bombing. It was carried live on radio and would have reached the broadest possible audience
