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Noise pollution can go beyond being an annoyance and actually harm human health. The demand for better acoustic building materials is growing and scientists at the Fraunhofer Institute for Building Physics (IBP) are working on the development of sound-absorbing micro-perforated materials that are aesthetically pleasing.
Noise pollution can lead to an array of health issues including hearing and vision problems, poor cognitive function, sleep disturbance, mental health problems, cardiovascular issues and trouble communicating. It can also negatively affect women’s physiological functions and it decreases most people’s ability to work efficiently.
Architects are eager to use sound-reducing materials but often complain that the materials available are inflexible and not very practical. The materials available are not very visually pleasing which limits the spaces where they can be used.
The micro-perforated construction components that IBP scientists are working on are suitable for all types of materials, allowing production of visually appealing sound absorbers. The technology make possible the manufacture of sound absorbers that are translucent and transparent.
On building façades or noise-cancelling structures, the materials will serve their function while fully integrating into the architecture of the buildings without detracting from the design.
IBP scientists are working on elastic surfaces that are made of side-by-side tubes with microscopically small spaces in between.
“It’s a bit like having a brush with bristles that are enhanced by little extra attachments at the ends, only much denser,” explains Dr Philip Leistner, head of the acoustics department at the IBP.
The new absorbent materials consist of perforated sheets with plenty of holes or slits. Friction is generated between the edge of the slits and the air in motion when sound hits the surface of the material. The resulting loss of energy results in sound absorption.
To avoid sound being reflected, there must be an air chamber behind the slits to allow molecules to continue oscillating once they have passed through the slits. The holes or slits can be punched, drilled or pricked into the material.
Particularly suitable for hygiene-sensitive areas, the pliable surface means that the micro-holes in the material can be cleaned with ease.
The components would come off the production line as a continuous length of material, making mounting easy and inexpensive.
“Above all, it’s a question of cost efficiency,” explains Leistner. “When it comes to ensuring the manufacturing process is cost effective, it’s important to realise that not all methods are equally well suited for every material.”
Fraunhofer scientists continue to develop the new materials which they presented prototypes of in January at the BAU 2013 construction trade fair in Munich.