Though sound masking systems have been used for over forty years and in thousands of facilities worldwide, they remain novel to many people; therefore, it is useful to provide a brief description of this technology.

Basically, sound masking systems consist of a series of speakers that distribute an electronically generated background sound within a facility. Many people refer to sound masking systems as white noise systems; however, this is a misnomer. The term white noise describes a very specific type of sound used in early sound masking systems developed in the 1970s. These systems were unsuccessful due to their inflexibility and the irritating hissing quality of the sound they produced, but the term white noise became widely adopted. Newer sound masking systems do not use a white noise signal; rather, they offer an engineered sound that is much more comfortable, unobtrusive and effective.

Sound masking addresses the lack of sufficient background sound that is characteristic of most office spaces. Among acoustic treatments, it is the only one that reduces noise disruptions and speech intelligibility by increasing the noise floor. All other acoustic treatments cause a reduction in the level of the noise itself.

Sound masking systems work because the ear cannot perceive simultaneous sounds of similar volume and frequency. Sound masking systems add a constant background sound across a wide frequency range in order to reduce intelligibility, decrease the dynamic range, provide an acceptable background sound level, and minimize the differences in the quality and level of sound across the facility. The result is that unwanted noises are more difficult, or impossible, to hear or comprehend.

As with all acoustic treatments, the benefits of sound masking systems are maximized when used in conjunction with other office noise control methods. Since sounds decay over distance, sound masking requires some distance to become effective, and this distance is minimized when sufficient physical barriers and absorptive materials are used in the design of the office. Furthermore, if absorption is increased, the sound masking system’s volume can be reduced without affecting its performance level.

Use of sound masking systems can reduce costs by eliminating the need for additional insulation, extra layers of drywall, plenum barriers, high-spec walls, or permanent walls around private offices. In this way, sound masking also maintains the flexibility of the office space for future renovations and changes. In open plan spaces, sound masking can help maintain a level of acoustic control as density increases and workstation partitions lower.