The atmosphere of a restaurant can be as essential to its success as the food it serves. Inappropriate décor or deafening noise levels can sour a guest’s dining experience, regardless of how tasty their meal may be. So restaurateurs often consult with everyone from sound engineers to historians to get the ambiance just right. We explore the serious considerations that go into restaurant design.
Local restaurants, bars and even libraries rely on noise to create an auditory experience. But how loud are each of these places, and how do they compare to one another? We traveled around Washington, D.C., with a sound level meter to see just how noisy the city really is.
First, a lesson in decibels. Loudness is measured in decibels, and most scientists agree hearing loss can occur when you have prolonged exposure – 8 hours or longer every day -- to a noise source over 90 decibals (dBA). This is why you see airport grounds crews wearing industrial headphones on the tarmac.
To the human ear, volume appears to double every 10 decibels. So jumping from 30 dB to 40 dB sounds twice as loud, but moving from 30 dB to 70 dB sounds 16 times as loud. For reference, a whispered voice is measured at 30 dB, while normal conversation is 60 dB.
We used a Brüel & Kjær Type 2250 meter and measured in one-third octave bands, taking the A-weighted value of all sound frequencies. All measurements were recorded by Andrew Parise, acoustical consultant at architectural consulting firm Shen Milsom & Wilke, and John Arpino, assistant director of engineering research and development at George Washington University.
We ranked 12 common D.C. experiences from quiet to loud. The measurements were taken on a warm Sunday afternoon in November when the restaurants and streets were busy.
Eckles Library: 33 dBA
As expected, this registered the lowest on our sound meter. The carpeted floor and rows of books no doubt helped to pad noise. Quiet students didn’t hurt, either.
Listening to WAMU 88.5: 64 dBA
This was measured while driving a car with the windows up and the radio set at a volume where we could comfortably talk with other passengers.
Starbucks: 66 dBA
This location’s upstairs seating area tempered the racket of coffee grinders, espresso machines and about 25 people making and waiting for drinks. The high ceiling created volume and distance that reduced the overall noise level.
Circa: 67 dBA
At brunch time, the restaurant was three-quarters full inside and had music playing over a stereo, but we could still talk at a comfortable level. It’s an airy space with a high ceiling made of drop tiles and other materials that help absorb sound.
Gravelly Point, planes taking off: 72 dBA
Gravelly Point, planes landing: 75 dBA
Joggers and picnickers raised their voices or stopped talking altogether as planes flew over this Arlington, Va., park on the edge of Reagan National Airport’s runway. You might expect these sound levels to be even higher; however most of the noise from oncoming planes is low frequency and less sensitive to the weighting curve that we used.
Firefly: 76 dBA
It's definitely loud in this low-ceilinged restaurant, and we had to yell at times to be heard. Wood is very bad at absorbing sound and very good at reflecting sound back into the room. Firefly had bare wood tables, hardwood floors and decorative wooden panels, all of which contributed to the din. To be fair, the restaurant was almost full and the door-sized front windows were closed -- opening them would have quieted the room.
Dupont Circle underpass: 77 dBA
Street noise at this intersection ranks around the noise level of a vacuum cleaner.
Union Station: 77 dBA
Hard stones, like marble, don’t absorb sound well inside this cavernous landmark. The measurement was taken as an announcement came over the loudspeaker.
Metro bus departing: 78 dBA
A bus pulling away from the curb, along with regular traffic, might grab your attention, but you can continue your conversation just fine.
Cleveland Park Bar and Grill: 79 dBA
Sports fans packed this bar to watch more than a dozen televisions showing every Sunday game.
Riding Metro: 80 dBA
Underground tunnels, plus heavy metal tires on heavy metal rails, were a cocktail for reflected sound as we took the Red Line from Farragut North to Metro Center.
Approaching Metro train: 85 dBA
A Red Line train pulling into the Dupont Circle platform is as loud as average street traffic, according to the American Tinnitus Association.
Of course, we're exposed to a number of everyday loud noise sources without suffering hearing loss. Hair dryers, snowmobiles, ambulances and fireworks exceed 85 dBA. Just as a landscape is what you see all around you, the soundscape is what you hear all around you. And D.C.’s soundscape is a blend of noise.