Modern management philosophy has moved away from private offices towards the use of open-plan offices and employee cubicles. (Nearly 75% of us now work in open-plan or bullpen type offices.) Without office wall barriers, sounds (primarily voices) are allowed to travel much more freely throughout the work space. Open plan offices, in combination with a quiet background ambient due to improved HVAC systems and noise efficient windows, result in noise being the number one inhibitor to workplace productivity.
Sound Masking is the most effective component in a total plan to reduce the understanding of conversations/speech intelligibility among workstations in an open-plan office setting. Sound masking involves the introduction of electronically produced frequency-balanced sounds (white noise) throughout the work space in order to increase the background sound level. This in turn drops the Speech Intelligibility Index (SII) to an acceptable level. SII is a weighted speech-to-noise ratio that indicates how well speech can be understood in the presence of noise. The index ranges from 0 to 1, where 0 is perfect privacy and 1 is perfect intelligibility. (See ASTM E 1374-02: Standard Guide for Open Office Acoustics).
Cubicle makers are also developing ways to restore privacy. Some offer extra-high cube walls and “visual privacy stackers” (to pile atop wall panels) to keep neighbors from peering in. Steelcase sells $800 “smoke screens” and a $2,000 sliding door to seal off a workstation’s entrance, and offers personal sound-masking systems.