"It's all in the mind," stated Shiranui, "Lance, Khuda, for both of your Ralts to start using these moves you need to help them with their mental focus as the mind is their greatest weapon.  Another facet of training a psychic is the telepathic link they can share with you and others.  If you hear voices in your mind, that's often a sign that a Psychic-type Pokémon is communicating with you through telepathy—also known in that context as mind speech."
"[i]Like what both Gallade and I can do,[/i]" added Titania through telepathy, projecting her mind speech to everyone in close proximity.
"The telepathic link can also help you understand Pokémon speech patterns and allow better communication," Shiranui continued, "For you, Khuda, once your Ralts is proficient at telepathy you can understand what your Mankey is saying through mind links."