Visual cues for in-game radio messages should be increased appropriately.

Currently, when a new call needs to be handled, in-game notifications rely primarily on audio (or, more accurately, almost entirely on audio), with only a small red dot appearing in the task list as a visual indicator.

This means that if audio is turned off (for example, due to the inability to use speakers or for the hearing-impaired), the game becomes virtually unplayable; even when playing normally with audio, players must locate the corresponding flight number in the task list in the bottom-right corner before proceeding.
Incidentally, for non-native English speakers, flight numbers are presented as text using universally recognized English and numerals, effectively eliminating any language barrier.

Although real-world ATC communication relies primarily on voice signals, I believe a game shouldn’t be overly fixated on realism and should consider adding more visual cues.
For example, a "To-Do List" could be added, extracting the red dots from the task list and displaying them as separate, prominent sticky notes. This would allow players to efficiently (1) determine if there are new pending tasks; and (2) locate and address the relevant tasks.