Voice volume changing randomly [Gameplay]

Sometimes when I do laugh or taunt emote, and on one occasion also affecting the Ekko's "heads up" that he says when he does his e, the voice is played as either an unheareable whisper or an eardefening shout, seemingly at random. It only happens very rarely, and so far this has only happened to me while playing as Lulu, but I have played a lot of Lulu lately, so it may not be that indicative.