Who do the gods talk to? How do they choose?

I think this is related to the questions such as "Why does Thor still use
a hammer as a symbol instead of a gun (still sounds like thunder &
lightning)?" 

I think that *part* of the answer to these questions is in something I
will call "affinity, receptiveness, and conditioning", but please don't
run to your dictionaries. Let me illustrate with some examples that may
not be untypical.

A kid grows up in a religious family, with a crucifix in his bedroom and
mass every week. One day he feels the need to pray for real & has a vision
of Jesus coming off the cross and lifting him up.

Another kid becomes totally absorbed in the Asatru lore and soaks up all
the details about all the gods. Some time later, she decides to fast for a
"spirit guide" and gets a vision of Thor striking the ground with his
hammer and making a canyon.

A third person attends a methodist church every week until he becomes
disillusioned and drifts off into a black separatist movement. He studies
native African religions as a way of asserting his racial heritage. His
visions are of an African god of agriculture.

How did that particular god come to communicate with that particular
person?

First, the person was receptive -- open to the experience of communication
with a divine being.

Second, the person may have had some kind of affinity for that particular
god, some kind of "fit"--temperament, interests, abilities, something. 

Third, the person's mind was "conditioned" and this is the tricky one to
explain what I mean. I think it is easier for gods to communicate with us
using symbols that are already significant to us--we know them and in some
way "believe" them. (Maybe that is the only what that they *can*
communicate with us, I don't know.) 

But how does Thor communicate with someone who has no concept of him
whatsoever? How can he identify himself or express his opinions? It is
certainly a lot easier if he can activate images that we already have.
Since we have an image of Thor and a hammer, it is the hammer that he uses
to represent himself to us.

So I think that part of the answer is probability. I am *more likely* to
become acquainted with and internalize the Asatru lore (i.e. become
conditioned with the symbols for Asatru) if my culture supports it, if the
lore is available for me to learn, and if, perhaps, I identify with those
stories because they remind me of myself, my family, or stories that my
family tells. And that makes it *more likely* that a particular As, Wan,
or Etin will manage to get a clear channel.