Service industries and construction

Acoustic architecture aims to ensure good sound quality in all types of building (administrative, leisure, business, residential etc..). The objective is to ensure the well-being of all users’ hearing and that of their neighbours.
The acoustics in a building depend on two types of sound which affect sound quality in different ways:

• Aerodynamic noise (internal and external)
•  Mechanical noise (shock, impact, vibration)

Sound is transmitted in three ways:

• Direct transmission through walls and partitions
• Interference transmitted through pipes, ducts and air openings
• Lateral transmission through floors and ceilings.

In terms of building acoustics, there are two essential (and often complementary) criteria to guarantee acoustic comfort: isolation and absorption

Acoustic isolation

Acoustic isolation consists of isolating an area from all noise, whether it comes from outside or from internal sources within the building. Isolating the area depends not only on the acoustic intensity level of the walls and partitions but also other types of sound transmission. Solutions for effectively isolating an area involve:

• Limiting direct transmission
• Limiting lateral transmission
• Limiting interference

There are many ways of limiting transmissions:

• Improving the acoustic intensity level of  dividing walls or partitions by making them thicker or by using multi-layered complexes
• Doubling walls and partitions by adding air space and material such as mineral wool
• Installing expanding joints to prevent vibrations
• Sealing all possible sound leaks through cable and tube passages, pipes and joints

Acoustic absorption

Acoustic absorption is characterised by sound travelling through an area where there is a source of noise. Wall, ceiling and floor coverings, as well as other objects in the area, significantly contribute to the acoustic comfort or to the noise pollution.

It is therefore essential to ensure the best sound absorption possible in a noisy area in order to limit the amount of time during which sound reverberates. This is particularly the case for industrial, leisure or professional activities such as meeting rooms, concert halls and other multi-purpose rooms.

Different types of material and various solutions can significantly reduce the amount of time during which sound reverberates, thereby improving the acoustic absorption of an area.

• Ceilings or suspended baffles (absorbent acoustic panels)
• Floor coverings (mats, carpets, resilients,  tiles)
• Wall coverings (plaster or perforated wood panels, soundproofing foam, gauze made of foam and other absorbent materials)
• Separation objects (mobile screens, office screens, curtains etc..)

The risks of hearing problems in the service sector are less well-known than those in the industrial sector. However, they are just as present in a large number of professional service activities.

For example: call centres, offices, open space and different types of administration spaces, services and also in sales.

Also, an important number of decrees have been ordered by the public authorities since 2000. The INRS (the National Institute of Research and Safety), one of our partners, has been working to highlight the problems of noise exposure in call centres (cf ND 2314-216-09 INRS).

An evaluation of sound exposure was completed in 2007 with the help of the CRAM (local health insurance organisations).

Workplace acoustics

There are two types of solution to protect people working in the service sector. Aside from the risk of hearing problems, noise is a factor which can cause stress, leading to common signs of stress like heart problems, digestive complaints, trouble sleeping, behavioural issues and impact on family life.

It can also contribute to a deterioration of work quality and company performance, when it has an impact on carrying out tasks, when it becomes an obstacle to communication and training and when it increases the number of errors, missed deadlines, absenteeism etc.

To this end, workspaces and workstations should be treated (thermal, acoustic, lighting) so that the noise levels do not exceed 55dB(A). Placing absorbent screens, the details of which would be defined according to the layout of operators, ceiling height, background noise.

• Restricting sound levels at source (noise limiters for call centre staff using headsets, soundproofing air-conditioning machines, ventilation systems, IT systems or any other mechanical noise source etc.)
• Reducing noise in the surroundings by improving and correcting the acoustics in workspaces and offices (installing acoustic screens, treating ceilings, walls, floors etc.)

Acoustics in offices are now governed by regulation NF S31-08, since 2006, which stipulates a sound level between 45 and 55 dB(A). The regulation NF EN ISO 11901 published in 2005 concerns noise exposure from sources placed near the ear. This applies in particular to call centre operators using headsets.

The attention that public authorities have placed on noise-related problems for people using headsets in call centres, mail order companies, information centres, breakdown services and for people working in Open Space and logistics centres enables these workers to be better protected from, and therefore limits their exposure to, risks of hearing problems.

ALFACOUSTIC has a wealth of experience in this area and has the expertise to develop the best solution for you to improve acoustics and restrict sound levels in your workplaces and offices in compliance with current regulations.