More than just a green facade: Vertical gardens for sound absorption and architectural acoustics

Noise can become uncomfortable for us in many situations both indoors and outdoors. External noise consists of activities (airplanes flying overhead, traffic on the road, etc.) that are either loud enough to be considered uncomfortable when outdoors, or are of an elevated volume to the extent that they infiltrate buildings at levels considered uncomfortable. In the case of internal uncomfortable noise, this can either stem from noisy activities that occur inside the building (people speaking loudly, printers, etc.), or when an unexpected sound suddenly permeates an area that has a very low level of background noise. The most common manner by which to mitigate excess noise is through the use of certain materials, which either insulate against noise passing through the material, or absorb the noise wavelengths. In the case of the latter, vertical gardens present themselves as not only an aesthetic element in architecture, but also as a potential acoustic control tool in building design. For this work 10 m2 of vertical garden substrate modules was tested in a full size reverberation chamber. The objective was to open the doors for vertical gardens to be used in architectural acoustic design.