The examination of tire/road noises at FKFS is not only carried out through far-field measurements with microphones besides the road, but also with a noise measuring trailer. Inside this trailer, in addition to the measuring wheels, there are a number of microphones, which measure the noise of the tire/road surface combinations directly where they arise. The system has considerable advantages compared to controlled and statistical pass-by tests. This way, measurements can be carried out very quickly, and other traffic flow has practically no influence on the results.

To investigate the tire/road noise inside the vehicle, a test bench is used at FKFS where sound fields recorded in advance at the tires are simulated using loudspeakers at the tire of the test vehicle. This allows to analyze the tire/road noise introduced from the outside without the disturbing influences of other vehicle noises.