In any large open public space, there’s a tendency for sound to carry, to the point where noises become distracting and private conversations can be overheard easily.

For this reason, most banks install sound masking systems. A sound masking system generates a uniform layer of “pink noise” at very specific frequencies. While this noise is too low to interfere with normal conversations, it does a great job of muffling extraneous sounds.

At Bank One in Madison, we installed a small equipment rack with pink noise generators and amplifiers, plus a relatively large number of omnidirectional speakers above the ceiling. To avoid a pulsing effect caused by the sound repeating on itself over time, we use two pink noise sources, alternating them every other speaker.

“In a sound masking system the speakers are above the ceiling and typically they’re not even pointed down,” says Henry Lewis. “You don’t want your listeners to know where it’s coming from. It’s everywhere.”

Our installers are alert for openings in the ceiling like light fixtures or vents that might cause the pink noise to be louder. In those cases, we even out the system using a dual-channel equalizer, which calibrates the pink noise to an overall level. With 60 to 65 decibels of pink noise above and around each cubicle, someone having a 40-decibel conversation doesn’t notice surrounding conversations and other noises.

Read more about sound masking systems.