“Noise control”, “soundproofing”, “acoustic mat”, “sound-insulating”, “sound-absorbing” – on site, these terms are used interchangeably. Yet when it comes to choosing a product and reading a specification, only two physical quantities matter: sound insulation and sound absorption. Anyone who keeps the two apart compares quotes correctly and avoids disappointing measurement results.
Noise control, soundproofing, acoustics – everyday synonyms
“Noise control” (German: Lärmschutz) and “soundproofing” (Schallschutz) describe the same goal: less sound where it causes a nuisance. There is no normative distinction between the two. What matters are the performance values a product brings with it – not the wording in the brochure.
Sound insulation: holding sound back
Sound insulation prevents sound from passing from one side of a wall, mat or sheet to the other. The key figure is the weighted sound reduction index Rw in decibels (EN ISO 10140 in the laboratory, or ISO 15186 Part 1/laboratory or Part 2/in situ, rated according to EN ISO 717-1) – the higher, the better. It is governed by the mass law: more mass per unit area (kg/m²) means better insulation. The spectrum adaptation terms C and Ctr describe the behaviour with mid- and low-frequency noise respectively (traffic, machinery). On site, the apparent sound reduction index R′w or DnT,w is measured; flanking transmission and gaps cost several decibels here.
Sound absorption: swallowing sound
Absorption works on the side where the sound is generated: open-pored layers (foam, fleece, polyester wadding) convert sound energy into heat and reduce reflections and reverberation. The key figure is the absorption coefficient α (0 to 1) or the weighted value αw with classes A to E according to EN ISO 11654 (A = best). αw = 0.4 means that 40 % of the incident energy is absorbed; αw = 1 corresponds to absorption class A – a weighted single-number rating, not “100 % at every frequency”.
Why both matter – and why the installation orientation is binding
Good noise barrier mats and acoustic panels combine both: a dense, heavy outer skin (insulates) and an absorbing layer facing the noise source (swallows). That is why the absorbing side always belongs towards the noise source. High insulation with low absorption means: good towards the outside, but strong reflections back into the work area. High absorption with low insulation: pleasant on the inside, but a lot of sound gets through to the outside.
Reading a specification correctly
- If the specification calls for an Rw: compare the laboratory value from the test report – a product property, independent of installation.
- If the specification states “x dB reduction” without a performance figure: usually a practical value under specific conditions; question the measurement conditions, distance and set-up.
- If the specification states an αw or an absorption class: relevant for enclosures and in enclosed work areas (reverberation).
- Fire behaviour: check the Euroclass to EN 13501-1 or B1 to DIN 4102 (German standard) where required.
Our products compared: noise barrier mats (16–23 dB sound reduction index, mass-spring-mass construction), mobile acoustic panel SILENCLOS® (R′w 20 dB, αw = 1) and mobile steel noise barriers. What the individual test standards mean is explained on the page Standards and test methods.
Frequently asked questions
What is the difference between noise control and soundproofing?
None – both terms (Lärmschutz and Schallschutz in German) mean reducing sound. What counts are the performance values Rw (insulation) and αw (absorption).
What is the Rw of a noise barrier mat?
The weighted sound reduction index measured in the laboratory – the value usually required in specifications. Depending on the version, our mats achieve 16, 20 or 23 dB.
What does αw mean?
The weighted sound absorption coefficient between 0 and 1. αw = 0.4 means 40 % absorption, αw = 1 almost complete absorption (class A).
Can the Rw be increased afterwards?
Yes, by adding mass per unit area – for example a second layer of mats (mass-spring-mass principle) or an additional heavy PVC layer.
Insulation or absorption – which do I need?
Both: the outer layer insulates, the inner layer absorbs. A high αw is particularly important for enclosures and indoor spaces, a high Rw for property boundaries.