Silence (revisited)

[Brownlie]

Sparrows cloud the sky, -- A strong image I see a large mass of birds covering the sky.
winged shadows of distant figments. -- How are the birds themselves shadows?
They fill the air with quiet, Quiet is the negation of sound, how can they fill the air with quiet? Perhaps this has to do with the essence of what quiet is?
their song caught in their throats. -- Can this sentiment be expressed in some sort of action of the birds like a movement of their head or something?

My voice has abandoned me too,
a bell that will not ring.
Words dying on my lips,
a tongue tied with filament. --I would consider getting rid of these last three lines. Once you've described that you're voice has abandoned you the rest seems redundant.

Tracing the birds flight,
I long for a single stanza.
Without your sound
the silence is overwhelming. -- I like the idea of silence as a sort of brooding pall it is very suspenseful, but I think these lines can be expressed more eloquently.

I may have missed your point, but it seems as if there is something here that has not yet come to fruition. Thanks for posting.