Non Stop Loud SPEAKER During Lesson

I went to lecture before and my attention was disturbed by people who were kept talking during the lecturer giving lecture. They speak like loudspeaker and talk all the time. I wonder if they ever get tired of speak almost the time?

Stay at the same hostel, same room and even same group, they spent time almost 24 hours together. Did they don't have enough time to speak? or maybe they have a lots of thing came out their mind to speak out. 

Why during class/ lecture? Talking among your friend while teacher/ professor explaining something is rude and sign of disrespect. Plus, you are disturbing others attention who really want to study. If you are coming to class/lecture to speak, please, you are most welcome not to come. No matter how smart are you, respect others.

You may speak as much as you want but not during lecture nor speak like natural speaker so that people around the world can hear you. Honestly, your voice is sort of sound pollution to other. So, please stop it