Tuning acoustical facade designs aiming for a controlled influence on the urban soundscape

The representative High-rise facades of today's major cities are composing an urban space out of glass and steel. With the reflection of one noise source on one hard reflective facade the noise level in an urban space can increase up to 3 dB. In the case of multiple reflections in a complex urban setting the level can increase up to 8 dB. Taking this effect into account the surfaces of inner city facades have to be redesigned aiming for an absorption of sound energy. Due to the different functions of a facade like outlook, light, energy and air the complete covering of a facade gaining for a broadband absorption is not realisable. If the demanded broadband absorption is not feasible the absorption effect can be tuned to several frequency bands in order to transform the uncomfortable noise perception into a comfortable one. During this research facade designs were developed with a focus on the acoustical effectiveness. It is shown that with a tuneable acoustical facade construction it is feasible to influence more than one frequency band gaining for a comfort soundscape in an urban space.