Sound Masking

Sound masking is the deliberate introduction of a controlled, uniform background sound into a space to reduce the intelligibility of unwanted speech and improve acoustic privacy. The masking sound is typically shaped pink or white noise delivered through loudspeakers installed above the ceiling. Per ASTM E1130, the masking spectrum is optimized to match the speech frequency range (200–5000 Hz) while remaining unobtrusive. Effective masking raises the ambient level by 3–10 dB to a target of 40–48 dB(A) in open-plan offices. This reduces the radius of distraction (the distance at which speech is intelligible) and improves speech privacy metrics such as Privacy Index. Sound masking is a component of the "ABC" approach: Absorb (acoustic treatment), Block (partitions), and Cover (masking). It is standard practice in open-plan offices, healthcare facilities (HIPAA compliance), and government buildings. Systems include networked digital processors with zone control and tuning capability.