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We at 4Silence believe that no one should suffer from the growing demand for mobility and the (increasing) traffic noise that comes with it.

That’s why we take pleasure in inventing, researching, and developing scientifically proven – and easy to install – noise reducing solutions for infrastructure. Like the WHIS®stone, WHIS®wall, WHIS®top and WHIS®barrier.

These three products reduce traffic noise in an entirely new way: by deflecting it. This is called diffraction. It makes noise reduction more elegant, durable, and (cost-)effective, helping more people enjoy peace and quiet in their environment.

The team

The 4Silence team consists of diverse specialists with one shared mission: making noise reduction through diffraction a reality. That way:

  • government can do its job better and easier;
  • contractors can install noise reducing products faster and more sustainably;
  • residents and travelers experience less noise and visual pollution.

Our people have (scientific) backgrounds in acoustical engineering, road and railway construction, and technical engineering.

We’re situated in Enschede, close to where we once started: Twente University. We’re down-to-earth, pragmatic, and hands-on. So we’re there for our customers day and night, and we never hesitate to pick up the pace if needed.

Want to know more about us? Please get in touch.

4Silence’s history



The WHIS®stone, WHIS®wall, and WHIS®top have been incorporated into law, making them available throughout the Netherlands. Meanwhile, we’ve started our first pilots in Belgium, Germany, and England.


The first WHIS®top is installed at Venlo.


4Silence is conducting a pilot in collaboration with Prorail.


Acoustic experts from TNO, M+P, DgMP, DB-Vision, Rijkswaterstaat, and Prorail, develop measurement and calculation requirements for 4Silence’s diffracting products, so they can become available in the GEOMilieu software package.


We translate diffraction into new products that reduce noise even further, like the WHIS®wall. At 1 meter in height, this screen reduces up to 9 dB.


We optimize the WHIS®stone and, together with Rijkswaterstaat and the RIVM, take the first steps towards incorporating diffraction into law.


The first independent pilots take place in Gelderland. The result turns out to be astonishing. The WHIS®stone, a roadside diffractor, has proven its effectiveness.


Ysbrand Wijnant develops the idea of ​​noise reduction of traffic noise by means of deflection: diffraction