Sound Masking for Speech Privacy

Sound Masking for Speech Privacy

Many open office areas employ electronic sound masking systems to create an even distribution of background noise that is just loud enough to help mask distracting noises (particularly from other conversations) without being loud enough to be a nuisance. The system typically consists of special loudspeakers mounted in or above the ceiling and a head-end unit that generates and shapes the noise. Another useful application of sound masking is to improve speech privacy between rooms. Privacy is traditionally assessed simply by using the Sound Transmission Class (STC) of the partition between two rooms. However, this is only part of the picture. Privacy is dictated both by how much sound passes through the partition (STC) and the background noise level in the receiving room. Obviously, it is easier to eavesdrop on a conversation if the receiving room is quiet. There are many situations where privacy is important and the background noise level can be used to our advantage. Speech privacy is important in healthcare where HIPAA requires that “reasonable safeguards” be taken to protect the privacy of patients’ personal healthcare information. The 2014 FGI Guidelines for Hospitals and Outpatient Facilities acknowledges the effect of background noise on privacy in the STC requirements between Exam Rooms. Table 1.2-6 requires STC 50 between Exam Rooms unless there is an electronic masking system, in which case only STC 40 is required. A 10-point difference in the STC rating is significant, and it may be less expensive to build STC 40 walls and install a sound masking system in an exam area than to build STC 50 walls and no masking. Sound masking can...