Comal, a bustling Oaxacan-inspired restaurant in Berkeley, California, has all the ingredients for the kind of ear-splitting ambience that’s become familiar in modern eateries: packed bar, open kitchen, high ceilings, and concrete walls. But when I join a dinner there one spring evening, it’s easy to jump into the margarita-fueled conversation and order up plates of grilled corn, carne asada tacos, and rotisserie chicken with mole.
Despite the clinking cutlery and up-tempo Latin rock music, nobody strains to hear the waitress when she points out the chipotle, habanero, and chile de arbol salsas that she plunks down with our chips.
This apparent sonic miracle is crafted by computer. An algorithm embedded in a system of networked microphones and speakers carefully controls the din. Called Constellation, the setup is the brainchild of San Francisco Bay Area firm Meyer Sound. The company, run by John and Helen Meyer, has built audio systems for concert halls, sports venues, and Broadway theaters for 40 years.
The couple first turned their ears to restaurant noise one night in 2010, when they met some good friends at an upscale tavern famed for its seasonal Mediterranean fare. The meal was superb. The racket of a packed house and an open kitchen was unbearable. Their table talk all but ceased.
While most people would just raise their voices for the evening and move on, John was inspired. He’d found their next challenge.
“We were trying to figure out exactly what interferes with conversation at the table,” John says. “What is the real problem? Why are people shouting?”
Ear-weary customers everywhere are asking the same questions. In the past decade, noise has risen to the top of annoyances in Zagat’s annual Dining Trends surveys, beating out poor service, bad food, and high prices. Restaurant critics in America’s major cities tote decibel meters to their meals. Apps like iHearU and SoundPrint help people vet their choices and share the results. Social media and mounting research about related health risks amplify complaints.
Diners might think the worst impact of a high-volume meal is a ruined night out, but University of Michigan public health researcher Rick Neitzel says eateries are part of a larger problem. Our cumulative sound exposure can increase our risk of hearing loss, heart attack, and stroke. “Your ears don’t care where the noise comes from,” he says. “They only care how much you get.”
It’s hard to pin down exactly how much extra volume is assaulting our eardrums when we eat out because most of the evidence is anecdotal. But consider a 1993 study of about a dozen dining establishments, which found that sound levels peaked at 68 decibels (a little louder than normal chitchat). Compare that with a much larger 2018 survey of New York City restaurants, in which one-quarter hit at least 81 decibels (more like a garbage disposal), the average level was 77, and just 10 percent were 70 decibels or below. The report deemed those “quiet.”
Saving dinner conversation isn’t as simple as turning down the in-house music. So some restaurateurs have started hiring consultants to diagnose their sonic ailments and prescribe a variety of architectural tweaks and sound-absorbing decor. A properly tuned environment ensures privacy for each table, and lets people chat and order in normal speaking voices—all without damping the buzz that keeps the atmosphere energetic.
John told Helen that, with the right tweaks, he could adapt Constellation—which Meyer had originally designed for concert venues—to offer a range of vibes for everything from a mellow Sunday brunch to a lively Saturday night. He and Helen began recording dinners at restaurants (with the owners’ OK) to find out what acoustic canvas they were starting with. In the center of the table, they’d plop a nest of six microphones crammed into what looked like a mesh flying saucer. The contraption captured the auditory mix from every angle so the team could later play it back and study it. Ultimately, they’d reverse-engineer the noise into something completely new.
The sprawling corporate campus of Meyer Sound was once a ketchup factory in the Berkeley flatlands. Inside a square block of low-slung, concrete buildings topped by red-tile roofs, massive factory floors with ample space for assembling speakers and other audio components surround a small, white-and-gray soundproofed chamber. This is the lab where the outfit’s handful of senior staff go to test out new ideas.
One morning, John Meyer sits in the middle of the room wearing a rumpled blue-checked shirt and tan chinos. Wire-rimmed glasses and an untamed gray beard frame his squinty, somewhat-distracted look as he peers at an array of wall-mounted speakers and dangling microphones. They’re attached to a computerized signal processor that can pick out threads of recorded sound (like the glug of pouring water or a loud laugh), modify their volume, echo, and location, and then weave them back together.
Senior scientist Roger Schwenke sits at a nearby computer. Schwenke develops hardware and software to predict and measure the acoustic effects of whatever system the firm creates. He cues up a demo of raw restaurant noise from one of the loudest rooms they’ve monitored: a busy Berkeley pizzeria. A couple of mouse clicks triggers an avalanche of chatter and music, through which intelligible bits of classic rock and debates about pie toppings briefly surface.
The shop peaks at 85 decibels, near power-tool territory but no longer unusual for American eateries. We can pin the din on converging trends that began in the 1990s. First, owners started favoring modernist or industrial looks. Out with carpeting, upholstery, and drapes that were great sound absorbers but now deemed stuffy. In with high ceilings, bare floors, and walls and furniture made of hard, sound-reflective materials like concrete, tile, metal, plaster, and glass, which send noise careening around the space.
At the same time, they merged dining rooms with open kitchens and bar areas, and cranked the music. Few reckoned with the sonic implications of these choices, according to Lily Wang, an expert in architectural acoustics and past president of the Acoustical Society of America, which shares research and develops standards for everything from hearing aids to classroom noise. “Architects aren’t trained to think about sound; they’re trained to think visually and spatially,” says Wang, who is participating in a nascent effort within the ASA to establish guidelines for restaurants.
Plus, some level of loudness seems to benefit the bottom line. Marketing research suggests that customers prefer places with lively background music, and they drink more alcohol and eat faster when the volume rises, boosting table turnover and revenue. Never mind that other studies suggest noise dulls our taste buds and leads us to favor fries over side salads and make other indulgent menu choices.
The racket is insidious in other ways too. As tables fill up and drinks flow, the ambient sound increases, causing diners to unconsciously raise their voices. This reflex, known in the acoustics industry as the Lombard effect, can start a vicious cycle. There’s no scientific consensus on the decibel level that triggers the phenomenon, but a 2018 study in a simulated restaurant found that voices started to swell when the volume ticked above 57.
At Meyer Sound, senior scientist Schwenke believes that “if the person next to you is intelligible and the people far away are less intelligible,” then your brain perceives less of a threat to you being understood, and you’re less likely to escalate to a Lombard cascade. Their challenge was to somehow modify Constellation to enhance each table’s conversation while simultaneously fuzzing out the rest.
“It was an experiment,” Meyer says of the effort, “but I knew there was a tremendous amount we could do.”
The next recording they play is from Comal. Owner John Paluska is a rarity among restaurateurs: As the former manager of the band Phish, he’d thought a lot about sound before opening the eatery in 2012. He hoped to create a fun ambience but knew that his design choices came with a real noise risk. He also wanted some acoustic control to fashion a high-spirited vibe near the bar and quieter areas toward the back of the place.
Paluska’s architect knew the Meyers because she and Helen had served together on a local school board. Helen showed Paluska some sound-absorbing panels and chatted about music systems. Then she demonstrated Constellation, which so far had been used only in concert halls to overcome sonic shortcomings, such as high-frequency tones from flutes and violins dying before reaching the final rows of seats.
At its core, Constellation is a sleight of hand pulled off by tweaking and redistributing reverb: the echoes we hear when sound waves spread from their sources and bounce from one surface to another. Absorbing these pings keeps audio from lingering, while digitally adding just a couple of seconds of echo can make a dead space in an auditorium ring like a cathedral nave. Helen calls this effect “invisible architecture.”
But restaurants present a more nuanced challenge. The sound doesn’t come from a stage; it comes from everywhere—and not everyone wants to listen to the same thing. For Constellation to help in this setting, the Meyer team would first need to deaden the space as much as possible. From that baseline, the system could capture, modify, and precisely tweak the clang from kitchens and noise from neighbors so diners could hear their own conversations.
Paluska was fine with being a guinea pig. Comal was still just a Berkeley storefront stripped down to its studs. The Meyer team began by squeezing in sound dampening wherever they could. Between exposed Douglas fir beams, they put 2-inch-thick rigid fiberglass insulation with a matte black finish so it would disappear. They hid wood-fiber insulation that resembles shredded wheat behind burlap wainscoting. And they printed the artwork—large abstract paintings and oversize Oaxacan street photography—on acoustically porous fabric stretched over sound-absorbing material in an aluminum frame. The Meyers call this proprietary product Libra panels.
Next, they wired up Constellation’s skeleton of 28 microphones and 95 speakers. They placed the mics as evenly as possible to cover each table while avoiding high-noise areas like the open kitchen. They positioned speakers so diners wouldn’t hear any of the outputs in isolation, instead catching a seamless sonic mix. The crew networked all these components through Constellation’s brain: a collection of digital signal processors that can each handle 100 gigaflops of data and combine to roughly equal the power of a dozen MacBook Pros. The computer knows which sounds come from which microphones, and lets Comal staff alter the sonic setting in real time from its iPad interface.
Imagine that you and a date are there on a crowded, buzzing Friday evening. Microphones above the table capture the vibrant mix of after-work gossip, clinking silverware and glasses, the guffaws of a raucous party nearby. The signal processor dampens and churns those sounds, and delivers them to speakers positioned in the far corners of the space. Meanwhile, ones close to you play a muted mix of room noises. This rerouting tricks your brain into focusing on your flirty banter. Constellation’s algorithm can also dim any sudden bursts that come from neighboring tables, or wash the most offensive clanks and rattles of the kitchen from the mix—all while leaving the background music alone.
At 80 decibels, the recording of Comal is definitely loud. Still, with Constellation activated, it’s easy to hear people at the table ordering jicama and cucumber salad, pork tacos, and tamales. Meanwhile, the droning ambience remained distant.
“It’s like you’re protected,” John Meyer observes. “It’s like a force field. And in a sense, it probably is, for the brain.”
Of course, it’s much easier to quell restaurant noise when you can start from scratch, rather than trying to tame the decibels of an existing eatery. For one thing, loud has become the new normal, making it easy for owners to dismiss.
Bob and Maggie Klein, for instance, had successfully run their Italian spot, Oliveto, in Oakland for more than two decades before discovering they had a volume problem. In the year leading up to a 2014 renovation, Bob decided to use a smartphone sound meter to spot-check busy dinner services, and found that they regularly hit 86 decibels. The number was comparable to other places he’d checked, but when Bob walked the dining room, he noticed people “leaning in and struggling to hear each other. And it’s common. It’s not just old people. It’s everybody.”
He empathized. A viral infection had badly damaged his hearing about 20 years ago, forcing him to use an assistive device. Even for people with healthy ears, though, listening in a crowded, noisy environment is tough. “You’re working so hard to hear the conversation that you’re not in the conversation,” he says.
The Kleins opted to install Constellation, joining a vanguard of owners moving toward better sonic management. According to Keely Siebein, a senior consultant with Siebein Acoustic, eateries are a rapidly growing clientele for firms like hers, which has nearly five times as many restaurant projects as it did a decade ago. Others in the field, the Meyers included, confirm the trend. Over the past five years, the ASA convention has held special sessions on the acoustics of dining establishments, leading to a working group on standards, which includes Siebein.
To date, seven owners have opted to install Constellation, which has a hefty price tag: between $60,000 and $80,000. The Meyers are working to cut the cost by streamlining the hardware and creating a cheaper alternative to the powerful signal processor needed for huge concert halls. For now, it’s a steep upfront investment for restaurateurs less motivated than the Kleins, who wanted to both improve diner comfort and gain the acoustic flexibility to host a variety of different events.
Meanwhile, there’s a range of more-affordable options that can help retrofit existing businesses. These include foam ceiling panels, perforated wood that allows noise to pass through to an absorbent layer, acoustic plaster with tiny fibers that will soak up reverb, and even a transparent, sound-dampening film for glass. The expense varies by material. According to acoustical consultant Nathaniel Fletcher, who works with the New York-based company AKRF, “It can go from a few thousand dollars to tens of thousands pretty quickly.”
At the fully renovated Oliveto, Bob Klein shows off the iPad from which he fine-tunes his restaurant’s sound. The system is set to “automatic occupancy,” so it adjusts in real time according to changes in the space’s overall noise levels. He easily moves through settings such as “symphony hall” (perfect for when Oliveto hosts classical violinists) and “cathedral” (used for a recent performance by the choral group Chanticleer). With each, Klein claps and lets the echoes ring in imaginary rafters. Other options favor certain microphones. For example, “panel discussion” activates only a row of mics above a rear area that can accommodate a long table; guests can easily take in forums on topical issues like genetically modified foods.
This range of configurations supports Klein’s vision of reimagining restaurants as community hubs. It hints at John Meyer’s ambitions too: controlling acoustics to give one architectural space the ability to feel like many. Tackling dining noise was his first chance to make sound behave in ways that brick-and-mortar alone can’t achieve, and still serve our auditory needs.
“We can create way more structure inside a high-powered computer than you can in the physical world,” Meyer says. “It opens up a whole way of creating spaces.”
This story originally published in the Noise, Winter 2019 issue of Popular Science.
