Unlike many workplaces, the office is a relatively quiet place to work. Two important benefits of good office acoustics are the ability to concentrate without being distracted, and the ability to hear the spoken word. Noise is a productivity issue as much as it is a safety issue.
The distinction between a sound and a noise is very subjective. It is particular to each person, and to time and place. Noise is best described as any unwanted sound. What may be a pleasant sound to one person, such as a stereo playing jazz, may be unpleasant noise to another.
The following chart shows the intensity of some common sounds:
|0||No sound||Hearing threshold|
|10||Rustle of leaf||Faint|
|50||Window Air Conditioner||Moderate|
|80||Computer print room|
|90||Heavy vehicle||Limit of exposure for 8 hrs|
|120||Propeller plane||Pain threshold|
|130||Riveting hammer||Feeling threshold|
|140||Jet engine at 30m||Danger|
* for average populations
Noise as an occupational hazard
Even at low levels, unwanted sounds can constitute health and safety hazards by increasing stress levels, and impairing communication and concentration. Sudden unexpected noises can startle and cause accidents. At high levels, noise can cause such problems as headaches, nausea and hearing loss.
Noise has been recognized as an occupational hazard in certain workplaces for many years. Noise exposure guidelines for the workplace are set to prevent exposure to sound at volumes that can cause hearing damage. The guidelines are typically given as the maximum duration of exposure permitted for various decibel levels. Sound levels in most offices are in the 45-60 dB range, well below the range for possible hearing damage.
Sources of noise in the office
Workplace sounds can be steady (such as the continuous hum from a ventilation system or a computer), intermittent (sound which comes and goes), or impact (sounds of short duration, such as the snap of an electric stapler).
A variety of sounds can be heard in the average office- anything from the sound of a ringing telephone to the background hum of a ventilation system. Some sources of noise can be minimized with minor adjustments. Others, such as the noise from the ventilation system, may require major alterations to building systems.
Sources of equipment-generated noise include telephones, photocopiers, computers, or other office equipment. Equipment-generated noise is usually transient and the sensitivity to equipment sounds varies from person to person. For example, the noise generated by running a photocopier may not annoy the operator, but it may be distracting to people in adjacent work spaces.
If you plan to purchase new office equipment, keep in mind the amount of noise produced. High-quality office equipment should function with a minimum of noise. Some types of equipment (e.g. photocopiers) will produce a lot of noise no matter what model you buy. Noisy equipment should be grouped together in an area away from workstations, preferably in a separate room. Don’t place noisy equipment against a hard wall or in a corner as the sound will be reflected back into the workplace.
Practise good maintenance to prevent noise from squeaking chair bearings, door hinges, moving equipment parts and other sources by lubricating them.
Occupant-generated sounds can be a major source of noise in the office. They include in-person as well as telephone conversations, radios, and movement within the office. Occupant-generated sounds can usually be dealt with by no more than a friendly reminder to keep the volume down. Encourage people to speak in lowered voices and to carry on conversations where they will not disturb others.
Music in the workplace, either from piped-in music or from a radio, is sometimes used to mask sounds. Music can provide mental stimulation while performing monotonous tasks which can help to reduce stress levels in the office. Some people, however, find music in the office intensely annoying.
Keep noise down!
Noise prevention begins with identifying all of the noise sources in the office. Remove the sources you can (e.g. lubricate that squeaking door). For those you can’t eliminate, take steps to prevent further propagation or amplification of noise.
Furnish walls, ceilings, and other large surfaces with sound absorptive materials. Use office dividers to reduce or redirect sound away from workstations. Soft floor surfaces will reduce noise. Heavy drapes or sound-absorbing wall decorations will also help.
When arranging the layout of workstations, allow sufficient space between them. They should be located away from high-traffic areas, so that people can work without being distracted. Define corridors with either partitions or free-standing screens. Avoid crowding too many workstations into one area.
Place screens, partitions, furniture, and office equipment for maximum acoustical benefits, with lighting and ventilation systems in mind. Screens should not block air diffusers or prevent ventilation. They should be raised off the floor to encourage air circulation. This does not affect their acoustical effectiveness; sound traveling under the screen is partly redirected or absorbed by office furniture and carpets.
Radio headsets can interfere with the ability to hear sounds which may alert the employee to a danger. Generally, radio headsets in the workplace or in traffic aren’t a good idea.
For more information on hearing: Better Hearing Institute, a US site that offers comprehensive information on hearing loss, tinnitus and hearing aids.