January 2014: Masking Sound

How many times have you lost your train of thought while typing due to a coworker talking on the phone nearby? How many minutes in a work day do you spend inadvertently listening to conversations from the next cubicle, or even from across the office? We’ve all lost work due to unwanted sounds, but background speech can prove to be even more distracting. Sound masking can help, but there is a lot of misinformation about these systems. Read on to learn how sound masking systems can be employed to great effect not only in open-plan offices, but also hospitals and hotels to improve productivity and comfort, and reduce aural distractions.

With new  building projects trying to reduce budgets wherever possible, thinner walls, partitions that end below the deck and other low-cost choices can be detrimental to sound isolation and privacy in a building, but can be audibly improved with the addition of sound masking.  These systems are also relatively inexpensive to implement and can easily be added to offices after construction.

To bury the hatchet in a common misconception, sound masking systems are not “white noise systems”.  White noise spectra contains high levels of high frequency sound, thus it is not pleasant on the ears nor is it conducive to productivity. Sound masking generators produce a tuned and equalized sound that is contoured to a similar frequency range to that of human speech. This does not mean that a sound masking system produces speech-like tones, which would be more distracting, but rather that it occupies the frequency range near human speech in order to “mask” conversations across the office.

Sound Masking Speaker

Sound masking does not eliminate all speech around an office, but only makes it more difficult to discern full words, sentences, etc. when spoken from a distance. In essence, the resulting sounds are less intelligible, so the talker’s conversation is more private and less intrusive to the office environment.

A sound masking system consists of a few key elements: a noise generator, an equalizer/processor, an amplifier, and a network of loudspeakers. Typically, speakers are installed in a ceiling plenum aimed upwards toward the deck. Sound diffuses in the plenum and down through the acoustic ceiling tile into the office areas to provide even coverage. For offices with open ceilings, speakers can be fired downwards (direct-field), but more speakers are needed to achieve an even sound field. Additionally, speakers can be zoned so that lower sound levels are provided to private offices with higher levels in open office areas, for example.

One of the best parts about sound masking systems is that the office occupants will likely never know it’s there.  Sound masking systems quickly become part of the background noise of an office and the sound levels generated by the speakers can be slowly ramped up over a month-long schedule so the occupants don’t notice the gradual changes in volume.

Sound masking is simpler than it seems, and when deployed correctly, can make all the difference in an office environment.

February 2014: Green is the New Gold
December 2013: Sounds of the Season