Strictly Confidential: The Cloud of Silence

The Cloud of Silence! No it has nothing to do with the Triads and it's not a criminal organisation, it's a privacy concept that has been considered for many years by sci-fi writers, film makers and Machiavellian managers.

The problem: how can you hold a confidential conversation in an open office without everyone overhearing? The answer that is being considered here is a device that will create an intimate 'cloud of silence' around the selected participants.

The proposed modern cloud of silence, we are assured, will work as it says on the box. It is being patented by engineers Joe Paradiso and Yasuhiro Ono of the Massachusetts Institute of Technology.

Patented solution
Their idea, revealed in US patent application 2009/0097671 on 16 April, is to make confidential conversations possible in open-plan offices and canteens, the two places most regularly occupied by US employees. It will even let a conversing group move around a room and still remain in a secure sound bubble, like a 'cloud of silence'.

"In open-plan offices, the violation of employees' privacy can often become an issue, as third parties overhear their conversations intentionally or unintentionally," the inventors say in their patent. Their aim is to relieve people of that concern. Presumably the intentional eavesdropper is going to have to make other arrangements or choose a new hobby.

The Plastic Dome scenario

Initially people considered using plastic domes, this was temporarily attempted but quickly fell out of favour, partly due to the obvious suffocation risk and the unbearable humidity. So, the idea of the plastic dome was scrapped but the name and the concept clung on, regardless. The need was still strong in them.

The Modern Solution
In the modern 'cloud of silence' they use a sensor network to work out where potential eavesdroppers are, and mini speakers to generate subtle masking sounds, at just the correct audible level.

It sounds simple, but it needs quite a bit of smart infrastructure. The walls of the room must be peppered with light-switch-sized units that include a microphone, a speaker, an infrared location sensor and networking circuitry connected to a server. When somebody wants to activate what the MIT researchers call the "sound shield", they do so on their desktop computer.

By responding to the position of the computer, the sensors identifies the person's location and maps out the locations of the other people around them. Smart software assesses who is so close that they must be participants in the conversation and who might be a potential eavesdropper.

The array of speakers then aims a mix of white noise and randomised office hubbub at the eavesdroppers. The subtle, confusing sound makes the conversation unintelligible or more unintelligible, depending on which of your colleagues is talking. Good luck! with this new system guys and success in replacing the older low-tech ways.

Low-tech solutions
Clearly, as a human, you will be able to see which of your colleagues around you is wearing their headphones, staring closely at their screen, whilst pounding the keyboard and is completely unaware that they are in the office at all. For convenience, we will call this colleague Troy.

From his behaviour you can quickly determine that he is not listening in on your chat. To further disguise your conversation and to drown out your voice completely, you should encourage Troy to sing along to whatever Country & Western album he is listening to. This is what is called 'white trash noise.'