I toyed with the idea of adjusting the pitch based on speed, but ended up not having time, unfortunately! What you're hearing is the natural pitching of my voice as my poor lungs expell their last ounce of air! Were we to implement that, it would probably be through code, assuming we could get the effect clean enough. I'd rather modulate it programatically rather than triple the file size of that asset or--gods forbid--try to replicate the same scream three times.