Ear licking is part of the sexual act, and the reason most listeners are listening is, among other things, to masturbate.
Some people say it's "very good for sleep induction," but if you look at the texts of those who are chatting enthusiastically from the beginning to the end of the stream, you know it's not true (even if it's an "unattended live stream" with just looping audio, lol).
And if someone's stream is off-camera, there is no way to distinguish between ear-licking and blow-job sounds, and if they show an illustration of ***** enlarged to fill the screen, you can tell that the purpose is to blatantly masturbate the viewer.

As stated in the guidelines, even if there is no visual image, if the audio is recognizable, it should be considered a prohibited act.
If there are operators who are not sure how to respond when they receive a report, the prohibited acts should be clearly stated so that they do not make the wrong decision.