When prospective customers visit the offices of Cambridge Sound Management for a demonstration of the company’s product, they experience it as soon as they walk through the doors. But they don’t notice it—and that means the product is working.
Cambridge Sound Management makes “sound masking” devices that attach to the ceiling and emit barely perceptible background noise that sounds similar to air lightly flowing through a vent, CEO Christopher Calisi says. During meetings with potential customers at the company’s Waltham, MA, headquarters, he presses a button, and it turns the system of sound-masking devices off.
“All of a sudden, they hear every conversation going on in every one of the work stations,” Calisi says.
Cambridge Sound Management is a classic example of an obscure company whose products operate behind the scenes, but are being used all over the place. The firm says it has more than 15,000 customers, including a significant chunk of the Fortune 100. Customers include large corporations such as Bank of America, Nike, Microsoft, and Southwest Airlines; elite universities such as Harvard and MIT; networks of hospitals and clinics including Spectrum Health; and government entities such as the U.S. Department of Education.
The company is also a reflection of the evolving needs of workers and companies as cubicles and flexible, open spaces have replaced private, closed-door offices.
The idea behind sound-masking devices made by Cambridge Sound, Advanced Network Devices, Lencore, LogiSon, and others, is to protect the privacy of conversations and reduce noise, thereby helping people concentrate and be more productive. The systems often incorporate other capabilities like office paging and background music.
Sound-masking technology helps hospitals, for example, protect sensitive patient information and potentially perform better on patient satisfaction surveys, which affect payments healthcare facilities receive from the federal government.
But the biggest revenue driver for the sound-masking industry is the evolution of office layouts. The sector began to gain traction a few decades ago as cubicles grew more popular, leading to noisier offices where workers sometimes struggle to tune out the conversations of their neighbors.
That problem has only grown more pronounced over the past decade, as companies and organizations of all sizes have opted for open office layouts that shorten or completely remove cubicle walls and cram workers closer together. The open office trend has been driven in part by the explosion of tech startups, co-working spaces, and incubators and accelerators; changing attitudes among the workforce; and a desire by large corporations to seem more hip and better attract young workers.
But while the intent of reducing barriers between workstations is to promote more teamwork and productive conversations, it can often have the opposite effect, Calisi says. He witnessed it a few years ago when he was consulting for a company. Two weeks after the cubicle walls were lowered, “I walked in the office one day and I want to say at least 50 percent of the people in their workstations all had headphones on,” he says. “The whole collaboration thing kind of went out the window.”
In many open-plan offices, headphones have become the de-facto do-not-disturb sign for workers who don’t have a door to shut for privacy and focus.
Cambridge Sound tries to address that problem by installing a network of three-inch wide devices spread throughout an office. Once mounted to the ceiling, the devices emit background sound at frequencies similar to human speech.
“Those frequencies are designed specifically to interfere with the human brain’s ability to comprehend the spoken word,” Calisi says. “It’s all about speech intelligibility.”
The result is a person can hold a conversation with someone less than 10 feet away, but they wouldn’t be able to make out the words of people talking throughout the rest of the office, Calisi says. As a Cambridge Sound acoustic expert explained in a 2014 Fast Company article, it creates an effect similar to the “hum” of cluttered sounds at a bustling coffee shop. That’s easier for the brain to tune out than clearly perceptible conversations and other noises from around the office.
“There’s a discernible increase in office productivity when [sound] masking is used,” Calisi says.
There are a few keys to making the system work. The background noise must be evenly spread out, Calisi says, so that it doesn’t become noticeably louder or softer as people move around the room, and so no one can discern the sound’s origin. Otherwise, the background noise will become conspicuous and annoying, he says.
“When we put a system in, our goal is that no one in the space even knows it’s there,” Calisi says. To that end, newly installed systems have a one-week “ramp period” in which the devices’ sound is initially set at a low volume and gradually raised until it reaches a target volume. “The only thing [clients’ employees] know—and they don’t know what to attribute it to—is they’re more comfortable in their work environments,” he adds.
Sound-masking systems for buildings date back to at least the 1960s. For years, the industry standard involved installing the background noise generators in the space above the ceiling where air gets circulated throughout the building, Cambridge Sound says.
The downside to that approach is it can be more expensive and require more time and effort to install. And since the sound must travel through the ceiling, air vents, and other structural barriers, trained acousticians must come in to tune the system so it accurately accounts for those impediments, Calisi says.
Cambridge Sound’s founder—Jack Heine, an MIT PhD who worked at Bolt, Beranek and Newman (now Raytheon BBN Technologies) for 30 years—came up with a sound-masking device that could be
