Deutsche Bahn wants to provide affected residents with the best possible relief from rail traffic noise. To make trains and facilities even quieter, DB is therefore working on innovative processes and optimized technologies, among other things. For many years, the so-called macrophone test was a significant source of noise for residents living near railroad facilities. The macrophone is the train's signal horn – also known colloquially as the horn or whistle. It warns people on platforms and at level crossings without barriers of approaching trains, for example.

Until now, train horns have been tested acoustically. Due to binding technical specifications, this macrophone test took place daily and often in the early hours of the morning while the trains were being prepared. This resulted in considerable noise pollution for the immediate vicinity of the railroad facilities.

Silent test procedure ensures noise reduction

In order to reduce noise for residents living near the depots and storage sidings, Deutsche Bahn is adapting the horn testing procedure across the industry together with the Association of German Transport Companies (VDV) and various other rail transport companies.

DB Regio and DB Fernverkehr have taken the lead and are already using the adapted alternative procedure. To this end, DB has subjected the series of its trains to an intensive technical analysis. As a result, it was determined that – with a few exceptions – the daily acoustic testing of the horns can be dispensed with. As part of the alternative test procedure, Deutsche Bahn continues to test all safety-related components and check diagnostic messages on a daily basis. This ensures function of the horns and meets all safety requirements.

The DB Regio fleet has been operating without daily acoustic testing since the beginning of 2024. DB Fernverkehr has dispensed with the daily acoustic test for more than 350 ICE multiple units since the end of 2024 and uses the silent procedure. With one exception: the ICE2 will continue to use the old procedure for safety reasons. In maintenance, the horns continue to be tested acoustically as standard. DB Cargo is also currently working intensively on testing the implementation as part of the industry-wide adaptation.