Solutions from Acoustic Comfort

There are a number of acoustic problems that affect people. It could be the space is too loud, or too quiet. Determining the problem enables a solution to be found.

Speech Privacy

An issue typically experienced in cellular spaces or closed offices, which is caused by sound leaking from the closed office into nearby spaces.

The problem often arises when the space is partitioned between the raised floor and underside of the ceiling, causing a large proportion of sound to leak into adjoining spaces. Base building design constraints, poor construction, lightweight partitions or a low building noise floor are also contributing factors.

Lack of speech privacy in a closed office

Speech privacy is particularly important in sectors where consultations must remain confidential, such as human resources, medical and financial.

Noise and concentration

This issue most commonly affects open-plan working areas.

This layout offers ways of working that enhance creativity, improve communication and boost team building. However, max-packed buildings with hard reflective interiors, continually reverberate sounds and staff suffer from an increase in background noise. A lack of walls and cubicles and uncarpeted floors further promote excessively high noise levels.

Noise affecting open plan areas

Because of this, designers, engineers and architects believe that quiet is good, but this is a major misconception. As office devices have got quieter, the measured sound levels in an open plan office are now often too low, and this too can be very unpleasant. Why? Because in very quiet spaces sounds are more noticeable and travel further. You will hear every keyboard stoke and conversation across the office, disturbing all within listening distance and forming a constant distraction.

Combined noise, concentration and speech privacy

The flexibility required by today’s businesses means most working environments have a combination of both issues – noise and concentration and speech privacy.

Contemporary work environments that make use of both closed and open plan spaces are cost effective and can help build good working relationships, but they do not always promote a successful acoustic environment. Typically a busy open office may be located in close proximity to quiet cellular offices or confidential meeting rooms, and noise travelling from one area to the other can prove extremely distracting for people occupying the space.

Noise affecting mixed use working environments

These agile working environments require careful design of their acoustic landscape to allow them to work together effectively.

Reverberation control

Reverberation consists of many reflections of a sound, maintaining the overall sound in a room for a time even after the direct sound has stopped.

Reverberation can cause problems in many types of building, particularly those with large, relatively empty spaces. Restaurants, bars, school halls, foyers, atriums, auditoriums and open-plan offices are all examples of spaces that commonly experience this issue.

Hard, reflective surfaces, such as glass, wood, metal and stone, cause sound to reverberate more. In a room with more acoustically reflective surfaces, it will take longer for the sound to die away, leaving the listener struggling with poor speech clarity.

The reverberant characteristic of a room is defined by the Reverberation Time RT60 which is the time it takes for the sound pressure level Lp (SPL) to decrease by 60 dB.

The optimum reverberation time depends on the size of the room and its activity. For classrooms and offices it can vary between 0.6 seconds and 1.3 seconds and for larger spaces such as concert and event halls it could be over 2 seconds.

In order to obtain the desired reverberation time sound absorbent materials are introduced onto the hard reflective surfaces. Depending on the amount used the reverberation time can be reduced to suit the room size and relevant activity.