Sophie's Science Experiment.

What makes a difference to the sound quality for a person listening on a mobile phone?

I think that you can't hear when there is wind and when you shout over the phone.

Experiment:

First I went far away from the person on the other phone. I could hear. Next I tried to listen in the wind. I could hear. Then I and some people shouted. I couldn't hear.

I found out you always could hear the sound but not when people are shouting very close to you as the listener.