Particular tone or rhythm in academic presentations
Everybody has to find their own style and "voice."  Perhaps in some people, that might come out in a sort of rhythm or tone.  In my own talks, when I am comfortable and happy with my material, I often settle into certain characteristic pattens of emphasis and pause, fast and slow. Watching people give good talks and studying their style can be a useful tool for figuring out how you relate to various tactics, and perhaps give you more comfort in their diversity, by showing that you do not have to strictly conform to any particular pattern. Your "voice," when you find it, however, will be uniquely your own.