Article: Innovative Noise Barrier Systems
MetaWindow
MetaWindow is the world's first noise barrier system to combine transparency with the acoustic performance of conventional highly absorptive noise barriers.
Developed in response to the requirements of the German infrastructure sector, this innovation resolves a long-standing challenge between effective noise mitigation, safety, attractive infrastructure design and public acceptance. Core of the system is the innovative arrangement of the sound-absorbing elements, which are positioned horizontally to maximise transparent surface areas. Unlike conventional highly absorptive noise barriers, where solid panels significantly restrict visibility, MetaWindow achieves a transparency ratio of approximately 58 % while maintaining the performance standards required of highly absorptive noise protection solutions.
MetaWindow Product Variants
MetaWindow is available in various absorption classes for both rail and road infrastructure applications.
- Highly Absorptive / High Reflection Reduction
- Provides reliable compliance with statutory noise emission limits. Conventional opaque systems can be replaced on a one-to-one basis without compromising acoustic performance.
- Absorptive
- A sound-absorbing system designed for areas with less demanding acoustic requirements.
- Reflective
- A sound-reflective system without sound-absorbing properties, intended for applications where sound insulation is the primary requirement.
Fields of application
Installing them along rail lines and roads brings advantages for both residents and passengers:
- in urban locations
- in tourist areas
- close to residential areas
- in attractive landscapes
The MetaWindow was developed by DB Bahnbau Gruppe in collaboration with the Italian start-up Phononic Vibes. The partnership developed from a startup contest with a subsequent funding phase by DB mindbox.
Diffractors
Efficient Noise Reduction Through Targeted Sound Diffraction
Diffractors utilise the physical principle of sound diffraction to influence the propagation of noise in a controlled manner. Their specially engineered geometry redirects sound waves at the top edge of the barrier, enhancing the acoustic effectiveness of noise protection systems.
This technology makes it possible to improve the performance of existing noise barriers or to achieve comparable levels of noise reduction with lower barrier heights. As a result, material requirements and construction interventions can be reduced, helping to lower project costs compared with conventional noise barrier solutions.
Diffractors provide a technically proven means of adapting noise mitigation measures to growing requirements while efficiently upgrading existing infrastructure. They are particularly valuable where height restrictions apply or where retrofit solutions are required, offering planners additional flexibility for the optimisation of noise protection systems.
Diffractor Product Variants
The Diffractor is available in various configurations for road infrastructure applications.
- WHIS®top - Add-on element for existing or new noise barriers
- The noise reduction performance of existing barriers can be increased by approximately 4-5 dB. Depending on project-specific parameters, new noise barriers can be constructed up to 2 metres lower, enabling potential construction cost savings of up to 40 %.
- When combined with conventional noise barriers, the WHIS®top add-on element offers several additional benefits:- Increased screening performance without significantly increasing barrier height- Retrofitting of existing noise barriers to improve acoustic performance- Suitable for structures with height restrictions or enhanced architectural requirements
- WHIS®wall - Low-height concrete wall with Diffractor attachment
- This 1.10 m high system delivers a noise reduction performance equivalent to a conventional noise barrier of approximately 3.0 m in height and can be installed without foundations.
- WHIS®barrier - Concrete vehicle restraint system with integrated Diffractor
- The system incorporates an integrated vehicle restraint barrier and provides acoustic performance comparable to that of a conventional noise barrier approximately 3.0 m high.
Fields of application
At present, no regulatory framework exists for the use of the system within rail infrastructure. Consequently, its application is currently limited to road infrastructure projects.
Typical applications along road transport corridors include:
- Residential areas located adjacent to motorways, trunk roads, regional roads and local roads
- Sensitive environments requiring enhanced protection, such as schools, childcare facilities and hospitals
- The development of new residential areas as a cost-effective alternative to conventional noise barriers
- Road sections where existing noise mitigation measures are to be upgraded or supplemented
The innovative WHIS® systems were developed by our Dutch partner 4Silence. We are convinced that these solutions deliver significant benefits for both infrastructure operators and local communities. For this reason, we contribute our expertise to further develop and establish these products for the German market in close collaboration with 4Silence.
End of the video above
Go