Telepathy
From L'avenir de l'humanité
From Contact Report 2
Semjase
28. Certainly there are such beings who communicate only telepathically.
29. However, their method of communication was telepathic from the very beginning, or else, they simply allowed their spoken language to become neglected.
30. But as far as we know, no beings who communicate only telepathically have ever come into terrestrial space.