I have a 15-year old, el cheapo Dean Evo electric guitar that's been sitting in a non-climate-controlled house for about a year. I pulled it out to play and immediately noticed that putting any pressure on the neck significantly caused the sound to warp. Specifically, pressure backwards towards my body. I don't remember it doing that in the past, so I'm wondering if maybe the bad climate caused damage somewhere.
Here's an un-amp'd audio sample where I variably put slightly more backwards pressure than you would just playing naturally: http://galen.in/VxH5rb
(I know the guitar itself isn't in great tune, what I'm trying to demonstrate is the warping in tone.)
Any ideas on what could be causing this? I thought maybe the truss rod needed adjusting and tried that after watching some tutorials on YouTube. I got the action better, but it's still warping. I know it's basically a throw-away guitar at this point, but it has sentimental value to me because it was the first guitar I ever bought and learned to play on.