What does it mean when a guy clears his throat when I'm sitting next to him?

[Anonymous]

This guy is in my class, and we have assigned seats. My seat is next to his. So every time we meet in class, I sit in my seat and I am minding my own business, I noticed that he simultaneously clearing his throat not loudly, but kind of in a way that its really low sounding, or he doesn't want to do it loudly because it's embarrassing or he is nervous. He does either with or without glancing at me often.

[Racez]

He's trying to "clear" his voice so that when talks with you, there's no stuttering in his voice.

Or he just wants to get your attention.

[luluniceone]

He wants to talk with you, he maybe shy or what. Primarily, he wants to catch your attention by that means or at least look at him.