Why two ears aren't too many

Someone said we have two ears and one mouth so that we listen twice as much as we talk. I think there are two far more important reasons for us to have been endowed with 2 ears -

1)So that humans have a pleasantly(or atleast presentably) symmetric face.

2)So that we can enjoy stereo sound !

Now, two mouths would be kinda hard to handle. Lets not get into that now.