Sound Masking

The Basics

How Sound Masking Works

Sound masking works because it changes the 'dynamic range' of sound in an environment.

Typically, the dynamic range in most environments is large, meaning that there is a great degree of difference between the lowest, or ambient, sound level and the highest levels of sound, when people are actively speaking and working. Offices are perceived as noisy precisely because of this large dynamic range. Here, the higher decibel (dB) sound of normal speech is easily heard in a backdrop of a lower, ambient background sound (dB level).

Sound masking works by subtlety raising the ambient background sound level, thereby reducing sound's dynamic range. This effectively "masks" unwanted noise, makes speech unintelligible (creating privacy), and makes the work environment acoustically comfortable.

For more on the dynamic range of sound, click here.

Complementing Speech with Added Sound
The electronic, background sound of a masking system is calibrated at 1-5 dB levels higher than the frequency range of incoming human speech (250 — 6,000 Hertz) from adjacent work areas. Lencore's Spectra™ performance range works from 20 — 20,000 Hz. Thus, by complementing the speech spectrum, conversations cannot be understood.

This graph reflects sound pressure levels in decibels, and the logarithmic frequency of typical speech patterns in hertz. The shaded area shows how Lencore Sound Masking systems effectively cover speech levels.

To ensure speech privacy, it is essential that the masking system's sound be balanced with the surrounding architecture (walls and partitions) and sound-absorbing furnishings (acoustical panels and ceiling tiles), to consistently produce a comfortable, uniform masking level. ASTM standards do exist for speech privacy, and Lencore has been proven by independent engineers to meet or exceed these standards.

Ready to check out sound masking for your facility? Contact Lencore to put a measurably better sound masking system in place!