4Silence

What 4Silence does

4Silence BV is a Netherlands-based deep-technology company that designs and manufactures sound-reduction solutions for infrastructure noise. Founded in 2012 and headquartered in Enschede, the firm's platform centres on a patented diffractor concept: slotted structures of varying depths that channel incident sound waves along their surfaces, induce resonance inside the slots, and create pressure differentials at the slot outlets that interfere with incoming waves and diffract noise upward. The result is a quieter zone behind the structure, achieved without tall screens or heavy construction.

The company sells six core products under the WHIS® brand — WHIS®top, WHIS®wall, WHIS®barrier, WHIS®stone, WHIS®damper (CLD), and WHIS®panel — each tailored to a specific deployment context (highway tops, walls, free-standing barriers, natural environments, bridge/infrastructure absorbers, and modular panels). All variants leverage the same underlying diffractor physics, with WHIS®damper extending into resonant-absorber technology. Customers are primarily public-sector transportation and urban infrastructure agencies, including national highways authorities, railway operators (ProRail, DB Bahn, Network Rail), and municipal governments in the Netherlands, Germany, the UK, Ireland, and Denmark. Distribution combines direct government sales with a growing network of regional partners (Gramm Barriers, Vibratec, Saferoad DK) and a recent entry into industrial noise control via Sealed Air.

The business model is project-based, quote-driven infrastructure sales with no public pricing or e-commerce channel. Revenue is non-recurring per project and tied to public-procurement cycles. A 2019 EISMEA grant of approximately $3.5M has been the only disclosed funding event, and the firm operates with 1–10 employees. Marketing relies on a multi-language website (Dutch, English, French, German), a project portfolio, technical downloads, and an acoustic calculation tool.

Name

4Silence

Legal name

4Silence BV

Website

https://4silence.nl

Company type

Private

Founded year

2012

Operating status

Operating

Headcount range

1–10 employees

Short description

4Silence BV is a Netherlands-based deep-technology firm that designs and sells patented diffractor-based noise-reduction products under the WHIS® brand to European government transportation and infrastructure agencies.

Ownership category

akta.pro rank

Product category

Acoustic Noise Reduction Infrastructure Products

akta.pro primary industry

Noise & Vibration Control for HVAC (Silencers/Isolation) (IMADANAL)

Keywords

• Noise reduction solutions
• Sound diffractor technology
• Infrastructure noise control
• Traffic noise mitigation
• Acoustic barriers

Headquarters

HQ city

Enschede

HQ country

Netherlands

HQ region

Europe

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Operations, Personnel, Marketing or Sales, Supply Chain

Distribution channels1 record

Marketing channels6 records

Core offering

4Silence designs, manufactures, and sells physical sound reduction products based on its patented WHIS® diffractor technology for infrastructure projects such as highways, railways, bridges, and urban environments. The portfolio includes six WHIS® product lines (WHIS®top, WHIS®wall, WHIS®barrier, WHIS®stone, WHIS®damper (CLD), WHIS®panel) that use slotted structures to create resonance and bend noise upward, delivering quieter zones without tall screens.

Product overview

4Silence is a provider of innovative noise reduction solutions based on patented diffractor technology. The product portfolio consists of six WHIS® branded products: WHIS®top, WHIS®wall, WHIS®barrier, WHIS®stone, WHIS®damper (CLD), and WHIS®panel. These products utilize slotted diffractor structures that induce resonance in sound waves, causing constructive interference that diffracts noise upward rather than allowing it to propagate, creating quieter zones behind the structures. The solutions are designed to be compact, visually unobtrusive, and environmentally sustainable, offering approximately 50% cost savings compared to traditional noise barriers while eliminating the need for tall screens or extensive construction work.

Differentiator

Problem solved

Functional benefit

Brands

• WHIS®: Product line prefix for noise reduction solutions including WHIS®top, WHIS®wall, WHIS®barrier, WHIS®stone, WHIS®damper (CLD), and WHIS®panel

Products and services

• WHIS®top Diffractor-based noise reduction solution designed to reduce traffic and infrastructure noise at the source; for government agencies, road operators, and infrastructure planners.
• WHIS®wall Wall-mounted diffractor system that reduces noise propagation through diffraction, creating quieter zones behind the structure; for highway, railway, and urban infrastructure projects.
• WHIS®barrier Free-standing noise barrier incorporating diffractor technology for effective sound reduction without requiring tall structures; for road and rail infrastructure operators.
• WHIS®stone Stone-style noise reduction solution integrating diffractor technology into aesthetically natural-looking structures; for environmentally sensitive areas and natural surroundings.
• WHIS®damper (CLD) Continuous linear damper (CLD) for bridge and infrastructure noise reduction using resonant absorber technology; for bridge operators and structural infrastructure owners.
• WHIS®panel Panel-based diffractor solution for modular noise reduction applications in various infrastructure settings; for infrastructure planners and contractors needing modular deployments.

Quantifiable outcome

• Approximately 50% cost savings compared to traditional noise reduction solutions

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature7 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Gramm Barriers: Gramm is a leading European manufacturer of noise barriers for road and rail infrastructure. Both companies target the same European transport-authority buyers with prefabricated barrier systems, and Gramm is already a listed partner of 4Silence, making it a head-to-head comparable.
• Saferoad Group: Saferoad is a Nordic-headquartered provider of road safety and noise-barrier solutions across Europe. It competes in the same infrastructure-noise mitigation category as 4Silence and is also a partner listed on 4Silence's website.
• Kohlhauer: Kohlhauer is a German manufacturer of transparent and conventional noise barrier systems for highways and railways. It serves the same DACH transport-authority customers as 4Silence with competing barrier technologies.
• Vibratec: Vibratec is a Dutch/Nordic acoustic-engineering firm providing vibration and noise control products for infrastructure. It overlaps with 4Silence's bridge-damper and barrier applications and is a disclosed partner of 4Silence.
• Akripol: Akripol is a Slovenian manufacturer of acrylic (PMMA) noise barriers used along European highways and railways. It directly competes with 4Silence's WHIS® wall/barrier products in transparent and lightweight acoustic barrier tenders.

Broad incumbents

• Evonik Industries: Evonik produces ROHACELL polymethacrylimide cores widely used in lightweight noise barrier panels for infrastructure. Although a chemicals giant, its ROHACELL product line competes directly with 4Silence's target applications inside large infrastructure projects.
• Sika AG: Sika is a global construction chemicals and building solutions company with acoustic and infrastructure products that compete in noise-mitigation projects. While broader than 4Silence, it supplies competing solutions into the same highway and rail tenders.

Others

• IAC Acoustics: IAC Acoustics is an established global supplier of noise control and acoustic products for industrial, architectural and infrastructure applications. It is a broad incumbent offering overlapping barrier/silencer products that compete with 4Silence in transport and urban noise projects.

Emerging players

• Echo Barrier: Echo Barrier produces temporary and portable noise barrier products for construction and infrastructure worksites. It addresses the same end-user pain points as 4Silence (cost-efficient, visually unobtrusive noise reduction) in a complementary use case.
• Phonotech: Phonotech manufactures acoustic panels and innovative sound-absorbing systems for building and infrastructure applications. It is a smaller, niche European player with overlapping acoustic-product technology comparable to 4Silence's WHIS® panel line.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks5 records

Key highlights6 records

Customer concentration

• YouTubeyoutube.com/user/4SilenceNL
• Facebookfacebook.com/107332822791071
• LinkedInlinkedin.com/company/4silence-bv

Revenue estimate

Valuation estimate

Number of profiles

Profiles3 records

Funding overview

Funding rounds1 record

Investors1 record

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about 4Silence