If you have a computer or other device in your house that needs lots of fans to stay cool you know how loud these fans can be. I have a computer in my office right now that sounds like a small jet idling on the runway. It gets quite annoying. A company called RotoSub is licensing tech that might be perfect for those that want some peace and quiet in the home or office.
RotoSub is a Swedish company and it makes an active noise cancellation system for cooling fans with tech that is sort of like what is used in headphones today. The active noise control (ANC) system the company uses doesn't have speakers outside the fan to cancel the noise produced, in fact is doesn't use speakers at all. The noise killing tech is inside the fan itself.
The tech is said to work so well that users are left with little more than the sound of the air passing through the fan. The system has no speakers to produce the antisound wave. The RotoSub system bends the blades of the fans in a way that makes the fan the antisound signal generator. The tech is said to make the fans no larger than traditional fans. The tech is being licensed to other companies for integration into gear now.