Mind Whisper is the codename used by Scytheon, the military division of Rossum Corporation. It involves taking former actives, specifically those who had been soldiers before signing on with the Dollhouse, and implanting them with a technology called Neuro-Radio, which enables everyone implanted with the technology to see and hear what the others see and hear as well as linking their thoughts in an almost telepathic fashion into a group mind. The result is that they become de-individualized drones, with a great tactical advantage provided by their link. (S2: "Stop-Loss")
The Mind Whisper program is diametrically opposite to the Dollhouse program within the Rossum Corporation. Where the latter seeks to imprint a number of personalities on to a single mind, the former's goal is to transform several minds into a single unified consciousness.