Whisper™, developed by SealedAir, is a closed-cell polyethylene acoustic foam with outstanding sound absorption performance. As an official distributor and converter, Flexicel offers Whisper™ in a wide range of thicknesses, formats, and finishes, including special surface treatments and custom-engineered solutions.
The World Health Organization has identified noise pollution as one of the most significant environmental issues of our time, second only to air pollution. Excessive noise can affect both physical and mental well-being, particularly in industrial, urban, and architectural environments with acoustically reflective surfaces.
What is Whisper®
Whisper™ (Stratocell® Whisper®) is an acoustic foam that is:
- Lightweight
- Water and moisture resistant
- Durable for indoor and outdoor use
- Broadband sound absorbing
Thanks to its closed-cell structure, it maintains its integrity where many open-cell materials may deteriorate.
Its high-performance honeycomb structure remains acoustically “flexible,” helping to reduce reverberation and echo even in humid or outdoor environments.
Unlike many traditional acoustic materials, Whisper® maintains its structure and performance when exposed to moisture, dirt, UV radiation, chlorine, and aggressive chemicals.
A unique acoustic solution
Whisper® sound-absorbing panels help to:
- Reduce ambient noise
- Improve speech intelligibility
- Enhance acoustic comfort
- Improve safety in industrial environments
- Create better acoustic experiences in public and private spaces
Noise pollution and frequencies
The World Health Organization has determined that noise pollution is a major environmental issue, second only to air pollution. Excessive noise can cause stress and negatively impact both physical and mental health. Noise is becoming an increasingly significant part of everyday life and should not be ignored.
Whisper® in action
Discover how Whisper® improves acoustic comfort and adapts to a wide range of technical and architectural applications.
Industry and Machinery
- Acoustic enclosures
- Technical housings and cabins
- HVAC systems
- Noise control in plenums and flanking paths (Rw up to 18 dB with 100 mm)
Architecture, Interior Design and Public Spaces
- Swimming pools, aquatic centers, and spas
- Commercial kitchens and restaurants
- Sports facilities, gyms, and arenas
- Reverberant spaces (multi-sport halls, museums, galleries)
Transportation and Rail
- Lightweight, impact-resistant solutions for trains (tested to EN 1794-1 and approved for speeds up to 300 km/h)
- Outdoor acoustic barriers resistant to UV exposure, hail, ice, and freeze-thaw cycles
Creative and Artistic Installations
Flexicel converts Whisper® using CNC machining, curved designs, custom geometries, and tailored formats for immersive experiences such as “Mundo Whisper”.
Technical performance
Certifications and testing
- ISO 354
- EN 13501
- DIN 4102
- UL94 HF1
- EN 1794-2
- EN 14389-1
- EN 14389-2
- 60721-3-4
Key properties
- Acoustic Class A–D
- Outdoor durability exceeding 50 years
- UV resistant
- Moisture and chemical resistant
- Lightweight and easy to install
- Washable surface
- Fiber-free
Sustainability and life cycle
Whisper™ provides a long service life, even in humid environments, reducing maintenance and replacement requirements.
Whisper® acoustic panels are designed to be recycled through post-industrial LDPE foam recycling systems.
In many applications, Whisper® can offer a lower carbon footprint compared with traditional mineral wool or polyester acoustic panels.
Download the Whisper® technical brochure
Learn more about Whisper® acoustic properties, applications, environmental resistance, and technical specifications.
Yes, Flexicel is an official distributor and processor of Whisper®.
Absolutely. Whisper® is resistant to moisture, condensation and intensive cleaning. For outdoor use, there is Whisper® UV.
Yes: Whisper® UV and UV-Eco, formulated for extreme climates.
Yes: technical laminates, colours, custom shapes and creative finishes (e.g.Mundo Whisper®).
Yes. Whisper® is certified to EN 45545-2 and is even used in systems approved for speeds of 300 km/h.
