Noise Protection

Sound Absorber

• Porous absorbers (mineral wool, melamine foams, metallic hollow sphere structures, porous road surfaces, fills, etc.)
  • material characteristics (measurement method, flow resistance, porosity, ...)
  • design of absorbers directly on the wall and at a distance from the wall Absorber covers (perforated sheets, ...)
  • design of absorbent curtains
• Micro-perforated absorbers
• Plate transducer and perforated plate transducer
  • Helmholtz-resonator
  • Quarter-wave-length resonator

• Absorptive silencer
  • designs (frequency response, transmission effect, ...),
  • approximate solution according to Piening nomograms,
  • flow noise,
  • pressure drop,
  • exact solution,
• Reactive silencer,
  • designs,
  • mode of operation,
  • insertion loss at the jump of cross-section,
  • insertion loss of a chamber,
  • insertion loss of a multi-chamber system,
  • Helmholtz-resonator and
  • Quarter-wave-length-resonator.

Encapsulation

• pathes of sound propagation,
• sound insulation of walls,
• openings,
• sealing,
• structure-borne noise insulation

Noise Barriers

• designs
• calculations according to Maekawa and Kurze (RLS 90, ISO 9613-2)
• calculation according to North 2000
• metrological evaluation according to DIN/CEN TS 1793-5
• absorptive of noise barriers and toppings

Outdoor Sound propagation

• calculations according to RLS 90 and  ISO 9613-2
• calculation according to North 2000