Does anybody know how to fix the problem when I make a call or someone calls me they can't hear me because their is a loud windy sound but I could hear them

I got a iphone7 and I have a problem when people call me or I call them they can't hear me only when I'm on speaker and I've searched for this and can't find anything on YouTube but I could hear the other person while they can't hear me please help I just got this phone