Sound absorption coefficient

January 2, 2026

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Nyquist Team

Comparing acoustic materials based on complex frequency charts can be difficult and unintuitive for investors. The sound absorption coefficient helps by reducing the material properties to a single, easily interpretable number, facilitating quick selection of solutions.

Professional Definition

The practical sound absorption coefficient reduced to a single numerical value according to the method specified in the PN-EN 11654 standard.

This usually refers to the weighted sound absorption indicator, denoted by the symbol αw (alpha w). This value ranges from 0.00 to 1.00, calculated by overlaying a reference curve on the measured values in octave bands. Based on this indicator, materials are assigned sound absorption classes (from A – highest, to E – lowest), allowing for quick categorization of building products.

Acoustics in Simple Words

This indicator acts like the absorption rating of a sponge, but in relation to sound rather than water. Imagine pouring a cup of water onto a surface:

A value of 0.00 represents a concrete floor or mirror – the water (sound) splashes and returns to the room almost entirely (total reflection).
A value of 1.00 represents a wide-open window frame – the water (sound) flies outside and nothing comes back (total absorption).

If an acoustic panel has an indicator of 0.80, it means that it

Nyquist Team

The Nyquist team is a group of enthusiasts in acoustics, design, and technology who combine engineering knowledge with aesthetic sensitivity every day. We create solutions that improve acoustic comfort and give spaces a unique character. On the blog, we share our experiences, knowledge, and inspirations drawn from our daily work on projects carried out across Poland and abroad. We believe that good acoustics is not just a technique – it’s a way of creating spaces where one simply enjoys being.

Nyquist Team

The Nyquist team is a group of enthusiasts in acoustics, design, and technology who combine engineering knowledge with aesthetic sensitivity every day. We create solutions that improve acoustic comfort and give spaces a unique character. On the blog, we share our experiences, knowledge, and inspirations drawn from our daily work on projects carried out across Poland and abroad. We believe that good acoustics is not just a technique – it’s a way of creating spaces where one simply enjoys being.

Nyquist Team

The Nyquist team is a group of enthusiasts in acoustics, design, and technology who combine engineering knowledge with aesthetic sensitivity every day. We create solutions that improve acoustic comfort and give spaces a unique character. On the blog, we share our experiences, knowledge, and inspirations drawn from our daily work on projects carried out across Poland and abroad. We believe that good acoustics is not just a technique – it’s a way of creating spaces where one simply enjoys being.

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