component that emits sound. Inadequate control may lead to elevated sound levels within the space which can be annoying and reduce speech intelligibility. Typical improvements are vibration isolation of mechanical equipment, and sound attenuators in ductwork. Sound masking can also be created by adjusting HVAC noise to a predetermined level. See also Noise health effects Noise mitigation Noise Reduction Coefficient Noise regulation Noise, vibration, and harshness Sound transmission class References Further reading Thompson, Emily (2002). The Soundscape of Modernity: Architectural Acoustics and the Culture of Listening in America, 1900–1933. Cambridge, Mass.: MIT Press. Acoustics Building engineering Acoustic problems Sound