The soundtrack The Winter Soldier describes the Winter Soldier perfectly. If you haven't heard the full soundtrack from Captain America: The Winter Soldier, here's a link.
It's starts off quiet; a dull ominous sound…
An eerie whine fills the air, fading away before coming back, like a ghost.
It fades back to the dull roar, and suddenly mechanical sounds are heard.
Whirring, twisting, scraping, buzzing. Fading...
His metal arm.
Whirring, twisting, scraping, buzzing. Fading...
…
Whirring, twisting, scraping, buzzing. Fading...
The shrill cry, again.
The music picks up, faster, faster, faster, like a speeding car. You can hear the engine.
He's on his way. You can't see him.
But he's there.
A break; a stall. Faster.
Beat, beat, beat!
The Winter Soldier is on the move.
Mechanical whirring and buzzing.
A screaming sound.
It fades…
Mechanical arm.
A scream. Drawn out, whining…
Beat, beat, beat.
All the while you can an ominous undertone.
He's coming.
The music sounds like an unstoppable force.
A scream.
Ominous, hopeless, dooming sounds.
Beat, beat, beat.
The wicked purr of an engine.
Ghost shilling. Fading.
Purr…
Ghost, ghost.
Beat, beat, beat. Rising climatically.
He is almost to you. You haven't time. But you don't know that.
He's a ghost.
Beat, beat beat.
Shrill.
DOOM, DOOM, DOOM.
Eerie cry…
DOOM, DOOM, DOOM.
Rising higher, and higher.
Louder cry! DOOM, DOOM, DOOM.
DOOM, DOOM, DOOM.
DOOM, DOOM, DOOM.
Repeating, over and over.
Up, nearly onto you.
You can't see him, but he's coming..
He's coming!
DOOM, DOOM, DOOM.
The cry!
DOOM, DOOM, DOOM!
You can't get away.
Another cry!
DOOM, DOOM, DOOM!
Yet another cry!
Rising!
Doom! Doom! Doom!
Rising!
Doom! Doom! Doom!
The cry!
Scream!
DOOM, DOOM, DOOM.
Hopeless!
DOOM, DOOM, DOOM.
But who is screaming?
His victims never get the chance to utter a sound.
DOOM, DOOM, DOOM!
Ghost shrill, almost static sounding— and then it's cut off suddenly.
…
…Silence.
The Winter Soldier has completed his mission.
Yet another soul screams.
As does his own.
A/N: This soundtrack touches me to the very depths of my soul. This roughly explains the meaning of it to me, I hope you get what I'm talking about. It's a little off, but if you read this in time to the parts in the music, it's really creepy. :)