Answer:
DR's speech was important historically because it prepared the United States for a shift in foreign policy from non-intervention (staying out of conflicts/affairs of other countries), and described the war happening in Europe as a threat the United States. The speech was powerful because it was centered around the American ideal of freedom and natural-born rights, and the responsibility of Americans to stay true to their values on the world stage.
The audio helps to contextualize the time in which the speech was written, due to both the sound quality (which is low) and the cadence and way of speaking that FDR has. FDR uses a specific delivery, including pauses for effect and changes in tone, to add to the rhetorical effect of his speech. Reading the speech does not communicate these things, although it allows the reader to reread certain parts and reflect more easily on the words (depending on how this person prefers to process information).
Step-by-step explanation: