Graillon FE is a new kind of voice octaver that tracks pitch frequency and mixes shifted copies of the input voice with itself.
Only the voiced part of the signal is changed (ie. vowels and voiced consonants). The unvoiced part of the signal (ie. voiceless consonants) is left untouched, to preserve the original speech's intent. For latency reasons, GRAILLON uses frequency-shifting as opposed to pitch-shifting. So the result will sound disharmonic, especially for the high notes.