Courtesy of Marpac

For nearly six decades, a beige, dome-shaped apparatus has lurked in bedrooms, offices, and waiting rooms, where it is heard but not seen. In fact, not noticing is what the electromechanical sound conditioner is all about. This unobtrusive device helps millions of Americans sleep and concentrate by hushing the world around them. Manufactured by the North Carolina company Marpac, the device has had a number of names in its lifetime—among them the Sleep-Mate, the Sound Screen, and the Sound-o-Sleep.

However, the sound it produces has never changed—a nimbus of noise opaque enough to mask intrusive sounds or private speech, but muffled and mellow enough to be forgotten. Today, rebranded as Dohm, the humble appliance holds its own in a crowded marketplace of digital comfort sounds, competing against ocean-wave machines and rainfall apps by being, well, more ignorable.

This post is adapted from Hagood’s new book.

The sound conditioner is one of the oldest examples of “personal therapy sensory devices”—the massagers, aromatherapy gadgets, air purifiers, and sound machines found in retail outlets like the Sharper Image catalog and Bed Bath & Beyond. The market for these technologies was said to be more than a billion dollars back in 2006, in a rare moment when someone bothered to study them. To better understand how and why Americans started plugging in machines to control what they hear and feel, I visited Marpac’s headquarters in Rocky Point, North Carolina, where I interviewed past and present owners, family members, and employees. There I learned the story of how noise was converted from an industrial by-product to a technology of self-care—the first entry in a now-bustling marketplace of devices attempting to free people from one din by creating a different one.


The sound conditioner was conceived in a roadside motel room circa 1960. James “Buck” and Gertrude “Trudy” Buckwalter, a young married couple, went sleepless because the room’s air conditioner was broken. According to Dave Theissen, Buckwalter’s protégé and eventual successor as Marpac’s president, the problem wasn’t heat—it was noise. Without the drone of the air conditioner, the sounds of an all-night poker game in an adjacent room kept the couple tossing and turning.

Buck was both a personable salesman and an inveterate tinkerer. He had risen to the position of vice president of sales at the Wooster Rubber Company (now known as Rubbermaid). Trudy told me he had also invented Wooster products such as the rubberized dish rack and rubber auto-floor mats. She had realized the sonic value of air conditioning and suggested that Buck invent something that made the same masking noise without cooling the air.

When the couple returned home, Buck began experimenting with a few household items: a plywood-and-carpet padding base he cut into a circle, the electrical supply and motor from a record turntable, fan blades he cut from a coffee-can lid, and a housing made from a tin saucepan. Buckwalter plugged his device into an electrical outlet and listened—the blades inside the pan whirred, circulating air in the housing and creating a muted whooshing sound. Using a can opener, Buckwalter made some openings in the housing, which increased both the volume and the frequency spectrum of the device. That night, the Buckwalters slept with the device on their nightstand, just as they did the next night, and the one after that.

According to Dave Theissen, the couple’s friends were soon asking for their own sound machines. That gave Buck the idea that a market existed for this variety of mechanical noise. He soon started his own company to pursue the opportunity. In 1964, Buckwalter and the investor William F. Lahey were awarded the patent for their “Sleep-Inducing Sound-Producing Device.” Lahey purchased his stake with $5,000, which enabled Buckwalter to buy injection molds for custom plastic housings, creating a polished-looking product that was easy to produce. Production speed was now of the essence, as Sears Roebuck had decided to carry the product in its Big Book catalog. Millions of sales later, you can find the Dohm online and on the shelves of stores such as Bed Bath & Beyond. It has become a perfectly natural household item.

What made the sound conditioner such a sleeper hit? After all, it was a fan that doesn’t blow air and a turntable that doesn’t play music. The answer relies on the unintended, sonic consequences of a cherished American value—freedom of choice.

Courtesy of Marpac

By World War II, the pursuit of consumer choice in the United States had generated a whole new soundscape. There were new forms of manufacturing and traffic noise, of course, but also new ways of measuring noise and controlling it, through architectural design, insulation, and acoustic ceiling panels. New media such as the telephone, the radio, records, and film soundtracks commodified sound like never before. During and after World War II, the military and economic need for speed in the circulation of people, goods, and information spurred innovations such as the jet airplane, the interstate highway system, the open-plan office, and television, all of which amplified and proliferated noise. As a result, people’s relationship to sound changed: They were subjected to a greater diversity of both pleasant and unpleasant sounds even as they became consumers of sound, critical listeners increasingly accustomed to making sonic choices based on aesthetics, audio fidelity, and environmental quality. The same forces of economic and consumer freedom that were generating the cacophony were also making people more sensitive to it.

By the time the Buckwalters invented the sound conditioner in the early 1960s, the study and “domestication” of noise—that is, its conversion from an unwanted industrial by-product into a useful resource—was well under way in the research labs of psychologists, acousticians, and telecommunications engineers, particularly at Harvard, MIT, and Bell Laboratories. Noise was harnessed as an analgesic in dentistry, a raw material for electronic music, and a conceptual and experimental tool in psychoacoustics.

But unlike these scientific and industrial innovations, Buckwalter’s sound conditioner represented a domestic domestication of noise, using the acoustical by-product of a spinning fan as a sonic shield for American bedrooms. In the decade and a half before Buck’s invention, urban dwellers had been abandoning cities. Economic growth, along with the developing highway system, racial fears, and the search for affordable housing, had helped fuel the drive to the suburbs. Air conditioning, the technology whose failure had inspired the Buckwalters, had also facilitated population expansion in the heretofore quiet Sun Belt. Among other things, people fled to the suburbs to avoid the noise of the city—the cars and trucks, the construction, the din of nightlife, and all the rest.

However, the retreat from urban noise had a tendency to reveal the fact that silence doesn’t really exist. Remove the background thrum of the city, and the snore of your spouse will suddenly stand out in stark relief. And even if you can achieve true silence, you’ll probably just hear the ringing and hissing of your own auditory system (people suffering from tinnitus are among Marpac’s most loyal customers). For Americans, whose senses had been tuned for the freedom to choose, it only made sense to eliminate such unchosen sounds. The Buckwalters had conceived a means of fighting noise with more noise to achieve a kind of personal sonic freedom.


Unlike the laboratories at Harvard and MIT, however, the 1960s home was not under the control of acoustical engineers. There the American housewife ruled the roost. Marpac therefore faced the additional challenge of domesticating noise culturallyfinding a place for it in the home. In fact, in its early years, Marpac refrained from using the word noise at all when describing the sound of its product, for fear it would seem to create the problem it was intended to solve. Instead, the company branded its product the Sleep-Mate and called it a “sound conditioner,” mirroring the atmospheric control provided by the air conditioner. Marpac’s advertising relied on images of women (often Trudy Buckwalter herself) sleeping peacefully with the sound conditioner beside them on the nightstand, both feminizing and domesticating the noise machine.

The domestication proved a little too successful. While firms such as Bolt, Beranek & Newman and Herman Miller were developing in-ceiling noise-masking systems for offices, these technologies had not made it to the average office worker seeking quiet for privacy or concentration. Because of this, Marpac began hearing from professionals who used the sound conditioner in their offices. Some felt that the Sleep-Mate badge on the top of the device did not give off a professional image. So the company spun off a second product, identical in every way but for the badge, which now bore the name “Sound Screen.” Marpac’s noise now provided the freedom to sleep at home and the freedom to concentrate at work.

In today’s hyper-mediated, 24/7 digital economy, an infinite array of informational and sensory options leaves people scattered and fatigued. That’s made technologies of self-care even more important. People often treat attention like a precious infant—something to be nourished and delighted, but also soothed, coddled, and carefully protected. The current Marpac owners, Jimmy Sloan and Gordon Wallace, told me that, in the 2010s, the company was selling more Dohms than ever. However, a multitude of other options have now arisen to block out noise, to manage your feelings, and, in the words of one Beats Electronics ad campaign, to allow you to “hear what you want.” There are digital white-noise and nature-sound apps, websites that put you in a quiet storm, simulated coffee shops, mood- and activity-specific playlists on Spotify, ASMR videos, and, of course, noise-canceling headphones.

If the hype proves warranted, a new category of in-ear products known as “hearables” will soon give people unprecedented control over what they hear. With some hearables—unlike the sound conditioner, whose broadband noise masks all sounds equally—developers aim to selectively cancel out only the sounds an individual chooses not to hear, vanquishing the crying baby on the airplane while allowing one to communicate with the flight attendant. Those efforts seem less like plugging one’s ears to distraction and more like erasing whole categories of people and everyday experiences. Compared with the never-ending array of digital choices for not listening, the mechanical noise the Buckwalters’ sound conditioner domesticated so long ago sounds comfortingly quaint.


This post is adapted from Hagood’s new book, Hush: Media and Sonic Self-Control.

This post appears courtesy of Object Lessons.

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