Noise measurement
DFS is not in charge of measuring noise. Such measurements are  made by airports and/or special companies on behalf of towns and municipal authorities, for example. The website of Frankfurt Airport, for example, provides detailed information regarding noise measurements.

Federal Aviation Office (Luftfahrt-Bundesamt  – LBA)
The Federal Aviation Office (LBA) is the supreme federal civil aviation authority in Germany. It comes under the administrative and technical supervision of the Federal Ministry of Transport, Building and Urban Development (BMVBS). It is based in Braunschweig, Germany, and comprises the five divisions Operations, Airworthiness / Environmental Protection, Aviation Personnel, Administration and Aviation Security, including their subordinate departments. The separate Office Air Navigation Services  (LBA-FS) is based in Langen, near Frankfurt. The Regional Offices of the LBA are located in Berlin, Düsseldorf, Frankfurt, Hamburg, Munich and Stuttgart.

Low drag/low power
Noise abatement procedures, such as low drag/low power are in place for approaches to Frankfurt Airport. This means that approaching aircraft stay in clean configuration as long as possible; landing gear, flaps and leading-edge slats will be extended as late as possible. This aerodynamic configuration only calls for little thrust. The more landing aids are deployed, the louder an aircraft is.