
"Repeated memory wipes fry your head eventually", which was the case for Dr Renfrew, whom the Silence used to keep Graystark Hall Orphanage open beyond its closing day. Any instruction spoken while a subject looked at a Silent, even a picture of one, would cause this effect. These orders would remain in a person's mind after they had forgotten the encounter with the Silent, acting like post-hypnotic suggestions. The Silents influenced the actions of others by issuing commands to anyone looking at them.
#A doctor claims humans were engneered ioff world upgrade#
( TV: The Impossible Astronaut) She appeared to upgrade the software later to make sure this didn't happen again. The Silents were also impervious to at least some types of scanning devices, as River Song's bio scanner did not detect them in the underground tunnels.

When the Doctor was unable to refresh Canton Everett Delaware III's memory of being told about the Silents, he forgot that the Doctor told him in the first place. According to the Doctor, even information about the Silents erases itself over time. ( TV: The Impossible Astronaut) Although any lifeform would forget the Silents when they weren't looking at them it was still possible to hear them, and people who knew they existed could listen for them in order to sense when they were nearby, as when River Song shot down a Silent without even looking at it. Similarly, after encountering several in a tunnel, River Song remembered long enough to climb a ladder in obvious fear before forgetting she ever saw them. While trapped in a bathroom with a Silent, Amy looked away for a few seconds a few times when the lights flickered or when talking with Joy and never forgot the Silent in the room with her. The amnesia appeared to take a few seconds before it took effect. Anyone looking at the Silents would recover their memories of previous sightings. They were uniquely "memory-proof" anyone who saw them would instantly forget about them the moment they looked away - even if they saw a photograph of a Silent. The Silents remained hidden on Earth for hundreds of thousands of years, since the early Stone Age. Powers and abilities Amnesia and hypnotic ability The renegade priests of the Kovarian Chapter wore black suits and ties in the style of 20th century male government workers on Earth ( TV: The Impossible Astronaut/ Day of the Moon) aboard the Papal Mainframe ship above Trenzalore, standard issue priests dressed wholly in black, wearing black suits with black high-collared shirts.

They spoke in deep, raspy voices, made growling or clicking noises, and as they breathed, they often produced highly eerie rattling sounds. Their eyes lacked sclera and were completely dark.

They had small eyes in deep recesses in the skull. Their hands had four large, spatulate fingers. They were tall humanoids, around seven feet tall, with bulbous heads and grey, mouthless faces.
