These are the characteristics of the Snow Man whom is named in the title of the poem. The speaker?
In fact, it is not quite either. For the listener, who listens in the snow, And, nothing himself, beholds Nothing that is not there and the nothing that is. The wind makes a sound as it hits the trees and leaves and land but there can be no true experience of it if that word misery is attached.
With a handy little tool called imagination.
Whoever it is they have the ability to listen and that listening is pure, there is no emotional language to color those sounds. Though we are shown three species, they all look essentially the same, and the poem's specificity only diminishes from this point on.
Ironically, then, we must consciously adjust our perspective and stop seeing the winter as a time of misery for Stevens, a false perspective and instead see it more neutrally but this is still a perspective, or way of viewing the winter world.
What exists beneath the subjective emotions and human-made designations that we impose on things?
Let's start with the listener, who is a male, that much is clear. Perhaps the speaker is suggesting that the listener, out there in that cold, bare landscape, is numbed and feels insignificant? Not only is it a magical take on a bleak reality but a profound exploration into levels of consciousness.
This shift from the visual regard, behold to the aural the sound of and with it the rejection of feeling is important because it signifies a withdrawal - nature is taking over - the emotional being, the human, the listener, becoming a snow man, like a figure in a painted landscape.
The book, and Stevens for that matter, exploded onto the scene and left American poetry reeling with his intellectual insight, mastery of imagery, and general awesomeness.