Sound Masking by Speech Privacy Systems: More Effective Privacy Through Better Sound Masking Technolog. Sound Masking from Speech Privacy Systems can give you an added edge by helping your workers become more productive, happier and less stressed.Sound masking is based on the phenomenon that when "low level background noise" is added to an environment, intruding speech and noises are less intelligible.Tinnitus is the perception of sound when no corresponding environmental sounds exists. It usually sounds like ringing, clicking or hissing in your ears.