I don't think you understood what I mean. I mean that if you have someone who speaks at a rate of x and that gets unintelligible at a playback speed of y and an

I don't think you understood what I mean. I mean that if you have someone who speaks at a rate of x and that gets unintelligible at a playback speed of y and another that speaks at a rate of 2x and gets unintelligible at a playback speed of y/2 then all other things being equal you have no advantage in listening to one instead of the other if you playback at the maximum intelligible speed.