As cities continue to expand and densify, understanding how buildings affect people’s perception and experience of the acoustic environment in context becomes more relevant. This paper presents a conceptual framework of the influ-ence of façades on the urban soundscape, based on the ISO 12913 series, in order to analyze the three main elements of the soundscape: people, acoustic environ-ment and context, along with façade as a fourth element. The methodology in-cluded literature review, as well as an exploration of the ISO 12913 methods for soundscape assessment via soundwalks and laboratory experiments involving a total of forty-three (n = 43) participants. The results provide a promising frame-work for façade analysis to progress toward the integration of human-centered approaches into the field of façade acoustics and complement current building physics practice.@en

People in cities are often exposed to complex mixtures of sounds, some originating from nature along with some created by human activities like traffic noise, sounds of industrial machinery, or music. This research aimed to study how the acoustic environment of a university campus is perceived by people. The procedures for soundscape data collection and analysis were based on the ISO 12913 series. 30 volunteers divided into four groups participated in a “soundwalk” at the campus of the architecture school in Detmold, Germany, filling out questionnaires while sound measurements and recordings were being taken. After the soundwalk, the data from the questionnaires, sound measurements, recordings, pictures and videos were analyzed. The findings suggest that people’s perception of sound is susceptible to the context, as participants seemed to shift their preference according to the ongoing activities that drew attention, such as a construction site, sounds from children playing, music and groups of people. The results provide new evidence and insights about the acoustic environment and the soundscape of the university campus and can inform stakeholders to improve environmental quality.@en

Diffusive surfaces can be optimally designed for both acoustic and aesthetic purposes. Adapting to the parametric demands of interface design, fractals are widely applied as a fusion of mathematical calculation and artistic design. The Sierpinski triangle is a self-similar structure with a more impressive appearance than conventional acoustic diffusers. However, the acoustic performance of Sierpinski fractal patterns has not been considered. This paper proposes a design of an acoustic diffuser based on the construction rules of the Sierpinski triangle to broaden the effective frequency range. The diffuser is made of triangular blocks of different sizes attached to a plane surface. A series of case studies are examined through numerical simulations based on the boundary element method (BEM) to investigate the effects of the number of iterations, the randomness of block arrangements, and the inclination of block tops. The diffusion performance of a conventional quadratic residue diffuser (QRD) is compared to confirm the advantage of the designed diffuser for broadening the effective frequency range. Furthermore, a workflow of the design and evaluation processes is presented to fabricate samples that could be used to tune the design parameters according to their in-field application demands.@en

This paper proposes a new design of an acoustic diffuser based on the construction rules of the Sierpinski triangle in order to broaden the effective diffusion frequency range. The diffuser is made of triangular blocks of different sizes attached to a plane surface. The effects of the number of fractal iterations, the height of triangular blocks, and arrangements of the blocks on the normal-incidence diffusion coefficients in the near field are examined through numerical simulations based on the boundary element method (BEM) in the frequency range of 100 Hz – 5 kHz. Furthermore, measurement results will be presented to validate the diffusion performance presented by the numerical simulations. The diffusion performance of a conventional quadratic residue diffuser (QRD) is compared to confirm the advantage of the designed diffuser for broadening the effective frequency range. It shows that the fractal patterns with various sizes of blocks improve diffusion performance compared to the conventional QRD of the same size, especially in the mid-low frequency range below 1 kHz.@en

Façades cover a significant amount of surfaces in cities and are in constant interaction with the acoustic environment. Noise pollution is one of the most concerning burdens for public health and wellbeing; however, façade acoustic performance is generally not considered in outdoor spaces, in contrast to indoor spaces. This study presents a systematic literature review examining 40 peer-reviewed papers regarding the effects of façades on the urban acoustic environment and the soundscape. Façades affect sound pressure levels and reverberation time in urban spaces and can affect people’s perception of the acoustic environment. The effects are classified into three groups: Effects of façades on the urban acoustic environment, including sound-reflecting, sound-absorbing and sound-producing effects; Effects of façades on the urban soundscape, including auditory and non-auditory effects; Effects of the context on the acoustic environment around façades, including boundary effects and atmospheric effects. @en