Technical terminology glossary:

REVERBERATION

Reverberation is the phenomenon in which sound persists in an enclosed space even after the original sound source has stopped emitting. This occurs because sound waves bounce off hard surfaces (walls, ceilings, and floors) and are repeatedly reflected before dissipating.
The duration and intensity of reverberation affect the clarity of sound in a room. In environments such as auditoriums, concert halls, or classrooms, controlling reverberation is crucial, as excess can cause echo, making hearing difficult and reducing sound quality.

ALPHA W

Alpha w (αw) is an index that measures the sound absorption capacity of a material, according to the ISO 11654 standard. This coefficient is used to express in a simplified manner how much sound a material absorbs on a scale from 0 to 1, where:
– αw of 0 indicates that the material does not absorb sound at all (totally reflective).
– αw of 1 indicates that the material absorbs sound completely (highly absorbent).
The αw value is calculated from sound absorption values at different frequencies, and allows materials to be classified into sound absorption classes (from A to E) according to their effectiveness in controlling reverberation.

NRC

NRC stands for Noise Reduction Coefficient. It is a measure that indicates how much sound a material absorbs, expressed as a number between 0 and 1:
– NRC of 0: the material reflects all sound (absorbs nothing).
– NRC of 1: the material absorbs all sound (total absorption).
For example, a material with an NRC of 0.80 absorbs 80% of the sound and reflects 20%. Materials with high NRC (0.7 and above) are commonly used in spaces where reverberation and echo need to be reduced, such as offices, auditoriums, and conference rooms. ASTM D5116: basis for conducting dynamic tests in environmental chambers to help determine volatile organic compound (VOC) emissions from indoor materials and products.

VOC EMISSIONS

VOC emissions refer to “Volatile Organic Compounds” (VOCs), which are chemical substances emitted by certain materials and products, such as paints, adhesives, and other construction materials. VOCs can affect indoor air quality and have health effects, which is why construction products are often regulated to limit these emissions.

DIN EN ISO 11654

DIN EN ISO 11654 is an international standard that classifies acoustic materials based on their ability to absorb sound. This standard assigns an “absorption class” that indicates the material’s effectiveness in reducing reverberation, ranging from class A (most absorbent) to class E.
When a product mentions VOC Emissions DIN EN ISO 11654, it refers to compliance with certain low volatile organic compound emission standards and has been classified according to this standard for its acoustic absorption capacity.

The standard UNE-EN ISO 354:2004 refers to a specific acoustic measurement standard. Its full title is:

“Acoustics. Measurement of sound absorption in a reverberation room”.

This standard describes the method for measuring the sound absorption of materials and objects in a reverberation room, which is a space designed for sound to reflect uniformly. It is used to evaluate the absorption capacity of materials (such as acoustic panels or coatings) that are used to reduce noise in enclosed spaces.

The elements of the standard indicate the following:

• UNE: Identifies that it is a standard approved by the Spanish Association for Standardization.
• EN: Indicates that it is a harmonized standard in Europe.
• ISO: Shows that it follows the standards of the International Organization for Standardization.
• 354: Is the number of the standard itself.
• 2004: Year it was published or updated.

Together, this standard is especially useful for manufacturers and designers of acoustic materials to ensure they meet quality and effectiveness standards in sound control.

PES

PES plastic is an engineering thermoplastic resistant to high temperatures with excellent temperature tolerance over extended periods. The PES polymer offers high mechanical strength and rigidity, as well as relatively low notch sensitivity.