Noise in a hotel can take many forms, from corridor footsteps to lobby reverberation and background noise in shared spaces. Ceilings, walls, furniture and flooring all contribute to acoustic comfort. This guide explains how carpet performance is expressed and how to read the test values for Kalida carpets.
How sound absorption is expressed
Sound absorption describes how much of the sound energy reaching a surface it absorbs. It is commonly expressed on a scale from 0 to 1, with higher values indicating greater absorption. However, not every figure on this scale is calculated in the same way. Always identify the indicator and measurement standard behind a value.
NRC and SAA
NRC, the Noise Reduction Coefficient, and SAA, the Sound Absorption Average, are indicators based on averages of absorption measurements at specified frequencies. NRC uses four frequencies within the speech range, while SAA covers a larger number of frequency bands. They help describe performance relevant to speech clarity and reverberation.
ISO 354 and sound absorption classes
Another approach uses measurements taken in a reverberation room under ISO 354. The results can be used to derive a single-number absorption value and a class from A to E. This is a different calculation from NRC, so the indicators should not be used interchangeably or compared as equivalent figures.
Acoustic values for our mosque and hotel carpets
Our mosque and hotel carpets have different constructions, so we present their acoustic values separately.
The measured values for our mosque carpets are NRC 0.40 and SAA 0.37.
For our hotel carpets, testing under ISO 354 produced a sound absorption value of 0.25 and a Class E result, recorded in acoustic report BLX-R-SA-28. This is not an NRC value and should not be compared directly with the NRC figure for our mosque carpets.
The influence of carpet construction
Acoustic behaviour is related to pile weight, pile height, weave density and installation method. Test values therefore apply to the construction that was measured. Our hotel carpets offer weave densities from 7 × 7 to 7 × 12 per inch, pile weights of 1,030–1,988 g/m², a pile height of 7 mm and total thickness of 9 mm. We can confirm the selected specification for your project at quotation stage.
Assessing hotel projects
Acoustic comfort is especially relevant in lobbies, corridors, meeting rooms and ballrooms. A carpet’s soft surface can help reduce the perception of footsteps, but the overall acoustics also depend on ceilings, walls and furniture. For a project with acoustic targets, review the carpet’s values alongside the relevant report and check which indicator is being used.
Acoustic figures are meaningful when their measurement methods are understood. We publish NRC and SAA values for mosque carpets, and the ISO 354-based absorption value and class for hotel carpets. Contact our team for specifications and test reports for the product suited to your project.