Focus on Acoustics: Speech Privacy for Open Plan Offices

Speech privacy is not only an important element of a good work environment — it is also critical to conducting business. From a confidential business meeting to tuning out your chatty coworker, providing the necessary levels of speech privacy is critical when designing any type of work environment. The biggest challenge is that most people work in open plan work environments. Private offices where sound can be more easily controlled are often not in the budget.  So how does one cope with this type of environment?

As outlined in our past newsletter article “Office Acoustics,” speech privacy is controlled by the signal-to-noise ratio of the offending source at a listener’s position. One way to reduce the signal-to-noise ratio and increase the level of speech privacy is to increase the background noise level of an environment (typically achieved with a sound masking or white noise system).

Other important aspects of open plan environments that significantly affect the speech privacy are:

  • Ceiling and Partition Material Types: Highly absorptive finishes in open plan environments can reduce the loudness of a noise source by about a third, or 6 dB for each doubling of distance from the source.
  • Partition Height: Partitions 60 inches high, while being a challenge for direct day lighting of a space, will significantly reduce the amount of direct sound being transferred throughout open plan office environments.
  • Worker Orientation: Locating two workers face-to-face at workstations vs. face-to-back can have a negative impact of 10 dB. For reference, a change in level of 10 dB is often perceived as a doubling of loudness, or reducing the loudness level by half, depending on if it is an addition or subtraction. There are many components to creating a successful work environment. And while open plan office environments are certainly not ideal for speech privacy, hopefully the tips above will help your next office renovation be a success.

edit-thorburn-headshot-0811Steve enjoys helping others understand the principals of acoustics and audiovisual technology almost as much as he enjoys sipping a good single malt scotch. He’s been InfoComm’s Educator of the Year, is a two-time InfoComm Facility Design Award Winner, author, teacher and has AV design experience on more than 2000 projects including Universal Studios Toon Lagoon, Hershey Park and Six Flags Great America. Find his company Thorburn Associates online at http://www.TA-Inc.com