Division 7.4.1 Boundary Characteristics linked to interior noise (BP20)

Noise levels in the driver's compartments must be kept as low as possible, by limiting noise at source through appropriate measures (acoustic insulation, sound absorption).

The L_eq equivalent continuous noise level measured over 30 minutes must not exceed 78 dB(A) in the drivers' cabs of motive power units running at speeds of 160 km/h.

When higher speeds are involved, every effort should be made to achieve the same value specified above.