Concept
Sound masking is the inclusion of generated sound (commonly, though inaccurately, referred to as "white noise" or "pink noise") into an environment to mask unwanted sound. It relies on auditory masking. Sound masking is not a form of active noise control (noise cancellation technique); however, it can reduce or eliminate the perception of sound. Sound masking is applied to an entire area to improve acoustical satisfaction, thus improving the acoustical privacy of the space. This can help an individual focus and thereby enhance productivity. Architectural acoustics Sound masking means controlling background sounds in a developed environment. It is significant and prioritizes modifying the background sound (in contrast to background noise); however, there is substantial evidence produced and published by Banneker (BBN) and Kavanaugh (et al., 1962 Speech Privacy in Buildings) indicating that acoustical satisfaction within a space cannot be guaranteed without consideration of the three principal parameters of architectural acoustical design, formalized and established in the early 1900s by Sabine. The three principal parameters are as follows (known as the 'ABC's' of architectural acoustics): A for Absorption – Sufficient (but not in excess) absorption in the developed environment. B for Blocking – Sufficient isolation of the developed environment. C for Control – Control of background sound levels in the developed environment. No single technique is effective in addressing every sound transmission path (direct, reflected, diffraction, transmission) and each varies in performance on a case-by-case basis. A sound masking system can be used to reduce the impression of intruding sound (reducing annoyance, distraction) and improve acoustic privacy (including speech privacy). However, there is a fundamental misconception in the deployment of a sound masking system in treating areas where there is a failure to appreciate the difference between the perception of privacy and speech privacy.