The concept of needing more energy when speaking a 2dn language really resonates with my experience: While learning English as a 2nd language, we noticed that

The concept of needing more energy when speaking a 2dn language really resonates with my experience: While learning English as a 2nd language, we noticed that when in a group of nonnative speaker, the who does the talking had a harder time understanding the native speakers than the others from the group. This never failed, whoever spoke had more problem to understand than he listeners. Maybe an explanation is that the extra cognitive energy uses to speak prevented as good comprehension as when fully spending the energy/focus on listening.