Acoustics in the Workplace

The floor is an important element in the room, which allows skilled specifiers to have a crucial influence on the room acoustics, without extra effort for planning and more expense. Particularly in working areas, where people spend most of their daily lives, the soft room factors and the atmosphere in the room play a large part in well-being and comfort and hence, ultimately, in productivity and creativity of staff. Room acoustics as a soft factor have been largely neglected out of anxiety about the usually complex issues. The team of advisors at ANKER will be glad to give you information personally and offers expert assistance for architects and specifiers.

Quiet. Please.

When a sound wave hits a surface, part of it is reflected, another part is absorbed by the surface material (converted into heat). This loss of energy is called absorption.

The degree of sound absorption is described by the αs figure and expresses the ratio of absorbed energy to incident energy. It is calculated according to frequency from 125 Hz to 4,000 Hz (in 6 octave values). A value of 0 corresponds to total reflection, a value of 1 to total absorption. Measurement is made according to DIN EN ISO 354.

Sound absorption is therefore very important, as it can be used to control the complex sound behaviour in a room.

As a rule, carpets are excellent sound absorbers and achieve values of up to 0.90 αs, depending on the frequency, which means that 90% of the sound energy is absorbed.

In comparison: with hard flooring, sound absorption generally lies at a maximum of 0.5 to 0.10 αs (= only 5–10% of sound energy is absorbed).

When carpets are also finished with special acoustic felt, sound absorption can be further improved by a factor of 4–5 in the lower frequency range at 500 Hz–1,000 Hz. This often helps to avoid expensive measures making use of acoustic fittings.

Depending on how a room is to be used, a recommended optimum reverberation time is aimed for. It is the time that passes until the sound level in a room drops by 60 dB. Reverberation occurs as a result of repeated sound reflections, which constantly become weaker with time. For rooms where musical events are held, it lies between 1.5–3.0 s, in offices at around 0.55 s.

By using appropriate products with adjusted sound absorption capacity, it is possible to achieve the required reverberation time.

Improvement for Every Step

Whereas sound absorption describes the acoustic situation inside a room, impact sound insulation concerns sound between adjacent rooms, in particular sound transmitted to rooms below. Measurement is made according to ISO 140-8.

Impact sound occurs when people walk on floors and stairs, but also when furniture or other objects are moved across the floor for instance. This noise can then be perceived clearly by those in adjacent rooms if insulation is poor. Carpets meet the statutory requirements for building projects without any special measures for fitting or additional insulating underlay. As a result, they contribute to an increased feeling of comfort and to greater concentration, and thus noticeably improve the working atmosphere. Noise is still one of the main causes of reduced efficiency in the workplace with, to some extent, adverse consequences for health.

Impact sound insulation indicates, in dB, how much a floor covering (as compared to the standard bare concrete floor) improves the values. With carpets it is possible to achieve values of 22–31 dB here without difficulty, whereas values for hard flooring are only between 4–10 dB without accessory fittings. An improvement of 10 dB in impact sound insulation means half the level of noise.

Sonicwave - For a Peaceful Working Environment

In order to be able to deliver even more effective sound absorption, ANKER has improved the already good acoustic properties of the carpet by using a special acoustic fleece. Thanks to the SonicWave finish we obtain an αw value that is up to 50% better than standard products. In addition, these products can also achieve 4–5 times higher levels of sound absorption at the lower frequency range of 500–1,000 Hz, compared with standard products. So a carpet with SonicWave can significantly reduce complicated and expensive measures that use acoustic fittings. Products with SonicWave are available as 400 cm wide broadloom carpet and as 60 x 60 cm tiles.

There are test reports available for all SonicWave products from the Aachen Institute for Acoustic and Thermal Testing (Schall- und Wärmemessstelle Aachen, VMPA Schallschutzprüfstelle DIN 4109) – both with regard to sound absorption in compliance with DIN EN ISO 354:2003 and impact sound in compliance with ISO 140-8.