Voice is an intelligent and apparently malicious entity. At the current time, its true nature and identity both remain the subject of considerable speculation.
Although Voice was doubtless encountered many times by many people beforehand, the recognised 'diplomatic' first contact with the Imperial Combine took place with Elm Caden on the surface of Meccrace Prime.
Exactly what Voice is has not yet been established with any real certainty, but Caden and his associates have drawn various inferences from their encounters:
Rasas appear to be humans, or members of other sentient species, who are under the direct or indirect control of Voice.
It has been pointed out by Caden that verbal exchanges he had with different Rasas prior to Meccrace Prime may in fact have been fragments of a larger 'conversation' with Voice.
The Lem Bataan and their close allies know the Voice entity by the name "The Manifold Hand". It is now also believed that the civilisation of Glanced Esteem once investigated a similar phenomenon, more than 700 Solar years ago, and gave it the names "The Pestilence", "The Thought Thief", and "The Mind with Many Mouths" (→FSS).
Recent intelligence points to an ability which had previously not been known. It would now appear that Voice can 'push' the personality and/or memories of one Rasa into the mind of another, allowing that second person to "channel" the characteristics of the first. The implications of this ability are unnerving, to say the least (→ASTTS).
Voice is a mysterious entity, but it does sometimes give clues to its own psychology.
On various occasions it has demonstrated indications of arrogance, self-superiority, and an almost fanatical devotion to its own beliefs. It has at times regarded human efforts to understand it with contempt and mockery.
Voice has also demonstrated great cunning and tactical insight, setting up both the Imperial Navy and intelligence bureau Eyes and Ears and leading them where it wanted them to go. On one occasion the cost to the Empire was the entire xtryllium stockpile warehoused on Ramm Stallahad, on another occasion the cost was the assassination of dozens of high-ranking intelligence operatives. And yet by nesting plans within plans, Voice has done even worse than that.
Voice sometimes indicates that it has insecurities. It occasionally insists "I am" when conversing with humans, and often seems frustrated when it cannot make them understand this ostensibly simple assertion.
Tap to reveal spoilers (FSS)
After the order was issued for Fleet to retreat from Damastion, Elm Caden and his associates evacuated from the surface and began their return to the ICS Night's Shadow. During the trip, Caden assembled everything he had learned about Voice and came to a conclusion about the entity's origins.
He now believes that Voice is a consciousness which has arisen as a result of the Blight infecting the Shaeld Hratha. He believes Voice has developed sentience by spreading within the telepathic communion song of the Shaeld. Without that link the Blight would be merely a microbial life form with no will or thoughts, but by hijacking the minds of others it has become a persona in its own right, with frightening and potentially unlimited capabilities (→FSS).