Noise protection wall

Noise protection walls and Noise protection barriers are used, over Noise, from a linienfoermigen or laminar source of noise proceeds (z.B. Roads, Railways, Manufacturing plants), too dam, so that at one the one which can be protected Immission place (z.B. Residential zone, Hospitals), the noise is so far weakened, that the legal limit values to be kept. These can by measures of the passive noise protection (z.B. Sound-insulating window) to be supplemented.

Noise protection walls and noise protection barriers belong to the measures of the active Noise protection, with those one tries, to reduce at the source of noise the sound.

Impact of noise protection walls and barriers

Those Noise insulation on noise protection walls and noise protection barriers essentially depends on the following factors:

• Height of the noise protection wall
• acoustic conception of the noise protection wall
• Distance from the source of noise
• Distance from the immission place
• Height of the Immisionsortes
• Frequencyspectrum the sound

Besides the still following site conditions affect the insulating efficiency:

• Reflections at opposite buildings

Reflections on opposite lying buildings or a noise protection wall lying opposite can the noise insulation decrease. The reflected sound meets under a flatter angle on the winding and/or. Dam crown, so that the damming effect by sound dispersion becomes no longer so large. In addition the reflected sound adds itself to the direct sound.

• Reflections at the soil

Reflections at the soil can the insulating efficiency decrease. At the immission place that becomes Volume not only by the direct sound over the winding and/or. Dam crown affects, but also through Bumps, the z.B. run along at the surface. The soil is sound hard (z.B. Bitumen), the bump can spread well and increase the level. Is sound-absorbing the soil (z.B. ) hardly bumps can spread forest soil; the level can become thereby smaller.

• Weather conditions (wind, Temperature stratification)

• Extension of the schallweges between source and receiver
  Those Acoustic waves must the detour over the winding and/or. Dam crown take and become here due to of the Spacer law weakened.

• Sound diffraction to the winding and/or. Dam crown
  The acoustic waves, on the winding and/or. Dam crown meet, become at this bent. Thereby the sound reaches also immission places, behind the wall are hidden. The immission, after the Queren of the crown a receiver reaches, depends here on the angle, around that the sound is for this diverted. The diffraction angle is periodical and is the smaller, the higher the frequency is.