A mind-voice is a mental voice rendered by the brain, but not spoken through the mouth. The mind-voice is commonly used when reading, writing, thinking and recalling conversations. A mind-voice is not a hallucination, but a thought. However, when combined with auto-hallucinatory training, it is possible for an individual to experience auditory hallucinations of mind-voices.
Mind-voice training is commonly applied to tulpas, in order to allow them to express themselves clearly to their hosts, by communicating through rendered words rather than thoughts. Teaching a tulpa to communicate through mind-voice has several advantages over communication by "raw thought", most prominently because it decreases ambiguity in its communication with the host. Communication through mind-voice is also considered to greatly reduce the effort involved in proxying.