The minimap seems to default to prioritizing objectives, but you can manually cast it by clicking their hero icon at the top of the screen (rather than clicking on their icon on the minimap)
So I just got out of a game where I kept randomly hearing an enemy player's "well played" voice line. I'd hear it, look at the chat, and get confused when there's no text in chat corresponding to the hero's voice lines. It was only at the end of the game that it clicked that they were spamming...