Sound absorbing wall - has helm-hole air body resonators and open cell concrete to absorb high and low frequencies

摘要

Sound absorbing wall (1) comprises layer of open-cell material facing traffic, having a relief, enlarging the surface for radiating sound. Resonance chambers (15) of helmholz air body resonators are located behind this surface which contain sound absorbing material (16). The open-cell material absorbs high frequency sound, and the helmholz air body resonators absorb low frequency sound. The panels are pref. formed from open cell concrete. The wall (1) can run alongside a road formed from open cell bitumen. @(11pp Dwg.No.9/12)@.