To reduce traffic noise, 4Silence developed a diffractor, the so called Whisstone. The Whisstone is a concrete element with cavities, which is installed next to the road surface. Instead of absorbing traffic noise, the diffractor diffracts it: it bends the noise upwards.
This significantly reduces the annoyance caused by roadside noise. The diffractor reduces tire/road noise by approximately 3 to 4 dB(A). The Whisstone is compatible with, and therefor a complement of, existing sound reducing measures, such as silent road surfaces and noise barriers.
“Sustainable noise reduction is always our goal”
University Twente spin-off 4Silence will bring new applications to market focused on reducing the annoyance caused by noise. Because they consider this to be important. Certainly now that technology offers increasing opportunities. The people from 4Silence see the advantages of innovation and translate these advantages into solutions in the area of noise reduction.
Related post: Solar Noise Barriers (SONOB)
Part of the Dutch Ministry of Infrastructure and the Environment, Rijkswaterstaat, started a pilot with the Whisstones at the highway A18/N18 (Zevenaar – Enschede) in the eastern part of The Netherlands.
— Rijkswaterstaat (@Rijkswaterstaat) 14 april 2016