Have you noticed that Riot did an outstanding job at informing us, players, invested in the match about EVERYTHING that is going on with audio, so that we don't have to take our eyes off the game to look at the HUD?
- when an ally dies, in addition to the kill feed, an audio cue is played (and, if in close enough proximity, an impossible-to-miss indicator proportionate to the distance pops up right around your crosshair, which you cannot miss)
- every agent's ult can be heard omnidirectionally (same volume regardless of position and distance) from the whole map
- for the last players alive, a loud and clear audio plays to tell them that they are the last so that they don't have to look at the character roster up top, and the enemy player(s) also get a similar notification about only 1 enemy remaining
- of course, another audio plays for the defending and attacking team when the spike is planted, further reducing the need of communication of trivial matters
- not only that, but - as obvious as it may be - a different audio plays for the agents' ulti depending on whether or not they are on your team or the enemy team, so that you can, again, hear the difference and prepare accordingly
- non-ult skills' audio can also be heard from quite the distance away, so players standing near to moderate distance away from the skill can hear it being used, even if the skill itself is out-of-sight for them (my guess would be that the skill is audible if inside the circle that shows up around your character on the minimap to indicate the audible range of your footsteps, but I might be wrong here; either that or remotely placeable skills have their own audio circle of the same size centered around the location they were placed)
- characters mutter some lines when they kill an enemy player, which, again, can be heard when inside the audible range of that character, so that you don't have to look at the kill feed to know if an enemy has been killed
These things might seem trivial, but after some 100 matches, the effect of these becomes VERY clear along with the fact that they help streamline the match experience for every player, avoiding the need to avert your eyes from the center of the screen and risk dying just to look at the HUD. Props to Riot for that one!
