Re: voice synth, I think that's just an artifact of how birds vocal chords (or whatever gizmo they've got in there) work. The timbre of the voice is going to be

Re: voice synth, I think that's just an artifact of how birds vocal chords (or whatever gizmo they've got in there) work. The timbre of the voice is going to be different than that of a primate. EDIT: you can even hear it in their natural calls, they have a buzzing, saw-like texture in the upper-mid and high range.