Welcome to Müller-BBM Active Sound Technology
Acoustics made easy - by superimposing two sound fields something new emerges. Usually, it will get louder - like two neighbors listening to music.
But sometimes the noise can also die away. For this effect both sound fields have to be equal, but reversely signed. Then they cancel themselves.
Müller-BBM Active Sound Technology takes advantage of this principle. We systematically produce such second sound fields, either to create silence or modified sounds. We use amplifiers and loudspeakers to create sound, digital signal processors to determine the right signal in realtime, and microphones for measuring the sum of both sound fields for control.
Unfortunately, this principle cannot be applied everywhere. Sound fields and sounds are often too complex for being inversely reproduced in this way. However, for some sounds it works in technical applications with reasonable effort, for example, for low frequency engine sounds in automobiles. This is exactly what we are working on.
Sometimes a little extra may be right. Sounds generate emotions, not only in music. And sounds give feedback on functions - the shutter noise of a digital camera as well as the clicking of an indicator in the car or the beeping of a backing truck. Sounds are part of the human-machine interface. We are working on their design and implementation for combustion engines as well as electric vehicles.