Phone calls are better, as no one can see the group on the other end looking at each other in bemusement (if in a meeting room) or in a group IM chat (if not all in the same place) asking each other what the hell the speaker is talking about (was talking about, as the speaker's often moved on). That's assuming anyone not interested has not taken a bathroom break.

Sarcasm I hope detected.

Speaking in an international environment is a skill. It's not just about (I think the term is) paralinquistics (speed, accent, volume, etc), it's about thinking about who else is in the conversation.