In an article for December’s issue of Sound & Communications, I tackle the belief that sound masking shouldn't be used in closed rooms such as private offices – an idea firmly rooted in the early 1970's, when the technology was first adopted to deal with noise in a rising number of open plan spaces.
At that time, most sound masking systems used a centralized architecture, which is really limited in terms of its ability to offer local control over volume and frequency. This technical impediment affected the masking’s performance in closed rooms, as well as the comfort of their occupants. Vendors and unhappy clients came to the conclusion that it simply couldn't be applied in these areas.
Despite the fact that decentralized and networked architectures went on to provide increasingly fine localized control – offering acoustic benefits that can’t otherwise be achieved in closed rooms – some people still argue that masking’s best left to open plans. There’s even one sound masking manufacturer that supports this opinion (hmmm…their system uses a centralized architecture).
I’d really like to put this debate to rest. And I’ll begin by saying that sound masking shouldn't be used as a ‘spot treatment.’
Some people joke (sort of) that they’d like to use it to address just the one person in their office with an unfortunately loud voice, but treatment of only particular areas (let alone people) within a facility runs contrary to a key design goal: occupants are supposed to forget that the sound masking’s there.
This goal can’t be achieved if there are noticeable voids in coverage. People can detect such changes as they walk between treated and untreated areas because the overall background sound level can vary by as much as 10 to 12 dBA. If, on the other hand, sound masking is installed in all occupied areas of a facility, a uniform sound level is maintained that, by virtue of consistency, isn’t noticed.
And this is only the first of many great reasons not to exclude closed rooms from masking designs. Check out my article “Sound Masking in Closed Spaces: Advances overcome myths and misconceptions” in Sound & Communications magazine or stay tuned for another post.