Terry: I'm beginning to feel a little like walking on eggshells here in my attempt to offer constructive feedback, so please don't take this wrong.

If a distracting type atonal (out of key) effect is really what you're after in your song, then fine, but (to emulate a hearbeat), I recommend replacing the 'pitched' (vibe) voice with a 'non pitched' type (drum:tom?) sound instead.

Utlizing a 'non pitched' type sound will eliminate the 'out of key' disonance that's currently going on when the chord harmony changes, yet the vibe's pitch doesn't. I really think your song has 'a lot' going for it, so sincerely hope you will re-consider making this minor change to your song so you (and others here) might hear and compare the difference yourself. Then again, I promise not to get my undies "bunched up" if you don't take me up on my suggestion either. - Scott