How does sound absorption work?
Sound absorption involves a material absorbing the energy of acoustic waves instead of reflecting them from its surface. When a sound wave reaches open-cell foam, it penetrates the material, where the acoustic energy is dispersed and partly converted into small amounts of heat.
The result is:
• reduced reverberation,
• less sound reflection,
• improved speech intelligibility,
• greater acoustic comfort indoors.
Verified sound absorption properties
The effectiveness of sound-absorbing materials is determined based on laboratory testing in accordance with the applicable standards. In the case of spray-applied open-cell foam, the following parameters have been obtained:
• Sound absorption class according to EN ISO 11654: D
• Weighted sound absorption coefficient according to EN ISO 11654: 0.50 (LH)
This means that the foam demonstrates a moderate level of sound absorption, particularly in the mid and high frequency ranges. In practice, this translates into a noticeable reduction in reverberation and improved acoustic comfort in residential and commercial interiors.
It is worth noting that αw = 0.50 means the material absorbs, on average, around 50% of the incident acoustic energy within the frequency range considered during classification. The (LH) designation indicates that the enhanced absorption properties also apply to low (L – Low) and high (H – High) frequencies within the range specified by the standard.
Sound absorption and sound insulation – an important distinction
Sound absorption means absorbing acoustic waves within a room, which reduces reverberation and improves acoustics.
Sound insulation means limiting the transmission of noise between rooms or from outside the building.
Open-cell foam primarily improves sound absorption. At the same time, as part of a complete building element (e.g. a stud wall or roof), it can also help improve the sound insulation performance of the entire structure. However, the foam layer alone does not constitute a barrier to high-intensity noise – the best results are achieved when it is combined with a properly designed building partition.
Where do the sound absorption properties of open-cell foam perform best?
Spray-applied open-cell foam is used wherever acoustic comfort matters.
It is most commonly used to insulate:
• converted lofts,
• partition walls,
• partition walls,
• timber floors,
• suspended ceilings.
In residential buildings, it helps reduce reverberation and improve acoustic conditions, making interiors more comfortable for work, study and rest.
Additional advantages of spray-applied open-cell foam
In addition to its acoustic properties, the material also offers a number of other benefits:
• excellent thermal insulation,
• tight filling – even in hard-to-reach areas,
• elimination of thermal bridges,
• low dead weight,
• good vapour permeability,
• durable performance characteristics,
• quick installation using spray application.
Thanks to spray application, the material adheres closely to the insulated surface, eliminating gaps that could impair both the thermal insulation and the acoustic performance of the building element.
Summary
Spray-applied open-cell foam is a material that effectively combines thermal insulation with improved acoustic comfort. Its properties are confirmed by test results in accordance with EN ISO 11654 – sound absorption class D and a weighted sound absorption coefficient αw >= 0.50 (LH). These parameters indicate that the foam effectively reduces reverberation and absorbs a significant proportion of acoustic energy, improving room usability and comfort. Combined with a properly designed building element, it is a valuable component of modern construction solutions that provide a high level of thermal and acoustic comfort.