Feedback on my accent, please (files attached)

Everyone,

I came to the US at age 12 and have lived here ever since (I'm 28 now). My goal is to have perfect American pronunciation; I want to sound like a true native American speaker and isolate and eliminate the nuances that cause many people to ask "Where are you from?".

I'd like to ask you to evaluate my current accent (it's fairly slight, since I've been living here since 12, but remains audible), and give me your comments and pointers.

Here are two clips with my speech -- I hope two is better than one, so you can better understand where my problems lie.

The first is a news article from the Washington Post, about Obama and McCain -
http://www.yousendit.com/download/Y2orWmdnNDRJMHZ2Wmc9PQ

The second is the "Sarah the Vet" paragraph that's often mentioned here as a tool to evaluate accents -
http://www.yousendit.com/download/Y2orWmdnNDRiV3hjR0E9PQ

Once I hear your comments, I'll share with you some of my own thoughts about my accent, and we'll see if we agree. I'd like to have a clear roadmap on what I specifically need to improve to sound 100% American. Thanks a lot!

I don't hear an accent. :) If anything, your pronunciation is more back in the throat which causes a bit of sqeaky sounds at a time. But I still don't hear an accent.

Thanks Estel. You're exactly right: my sounds come from the back of the throat, resulting in a deep tone that's a little unnatural in American English. I've read somewhere that the key is to make sounds come out of "the middle" of the throat. Any ideas how to do that? I mean, my voice is my voice, I can't change that.

I'm also having some trouble with the initial "t" sound, I exaggerate it and resonate it a little too much I think. I put my tongue on the alveolar ridge right behind the front teeth, and I think this is how you're supposed to pronounce it, but for some reason it comes out a little too "explosive". When I listen to native speakers I'm not distracted by any explosive sounds, but in my speech I am.

By the way, are you a native American-born speaker yourself?

Thanks again for the feedback.

I don't hear an accent either but are you from India or Middle East?

No. I'm originally from Russia.

By the way, please identify in your reply whether you are a native American speaker yourself. This is very important; some non-native speakers can miss an accent where there is one. Thanks.

I do hear my accent, and as others have pointed out, it seems to be the deep quality of the voice, I'm not resonating words where I should be. Any pointers from American-born native speakers?