The software tool is called a phase “vocoder” (vocoder is a made-up word consisting of the union of “voice” and “encoder”), a means to digitally encode vocal audio streams.
This application of autotune is quite interesting and melodic.
I like this one below, where they make it appear as if Jane Goodall is singing:
Jane Goodall with Don & Janet Burleson
Check this out, worth a watch:
