https://www.gamespot.com/articles/madden-18-update-adds-a-big-new-feature-and-more/1100-6455566/

Months after its release in August, EA Sports continues to update and expand Madden NFL 18. The game's newest update is out now on PlayStation 4 and Xbox One, adding a major new feature and online stability improvements, among other things.

The big new feature is called "Audibles on the Fly." As the name suggests, this lets players make a change to an audible at any point when they are on offense or defense. EA says this will add a further level of strategy for advanced-level players. The idea is that you'll be able to make ever further quick adjustments when you see how the other side lines up.