Ahem is the sound people make when they clear their throat to get attention or signal something without actually saying words. It's that little cough-like noise someone makes when they want you to notice them or when they think you're doing something you shouldn't be doing.

Teachers use it constantly. When the classroom gets too loud, a teacher might say “Ahem!” instead of shouting for quiet. When you're whispering during a presentation, you might hear an ahem from the front of the room, a polite but unmistakable signal that means “I see what you're doing, and you should stop.”

People also say ahem when they're about to correct someone or point out an awkward truth. If your brother claims he never loses at chess, you might clear your throat and say, “Ahem, what about last Tuesday?” It's a way of saying “excuse me, but I have something to add” without being too direct.

The sound can carry a knowing quality. When someone says ahem, they're using that sound as a gentle (or sometimes not so gentle) way of saying “pay attention” or “think again about what you just said.” They're communicating deliberately, choosing this sound to send a specific message.