Reducing Restaurant Noise Levels With Acoustic Panels

Primacoustic restaurant rise in db levels

Problem: The increasing incidence of high dB levels that lead to restaurant noise was once again the number one complaint patrons have with restaurants, as confirmed in a recent Zagat survey. The seriousness of this problem is highlighted by the fact that many food writers are now including decibel level readings in their reviews.

This leads many to ask the question, “Why are some restaurants so loud?” Design and decor is often the culprit in too-high noise levels that occur.

Modern trends in high ceilings and hard surfaces compound the issue of restaurant owners locating the business in a building or space that wasn’t designed for good acoustics. Too often, these owners are faced with a difficult decision down the road, based on complaints and diminishing customers due to noise levels — incur a significant and expensive renovation of walls, ceilings, and fixtures. Thankfully, as this interview with Primacoustic’s Steve Dickson shows, restaurant owners have an alternative to the cost of major renovation: acoustic treatment and sound absorption panels.

Solution: Installation of sound absorption panels are increasingly becoming a popular option for restaurant owners who want to address high dB levels. While sound absorption panels can’t (and don’t) alter the dB level of the original source, the panels can (and do) reduce the ambient level from the reverberation effect that occurs as sound bounces off hard surfaces such as glass, countertops, tables etc.

In this interview with Primacoustic’s Steve Dickson, we discuss the issue of restaurant noise and what can be done to address it.

What Makes Some Restaurants Really Loud?

Primacoustic: What can a sound absorption panel do to address restaurant noise?

Steve Dickson of PrimacousticSteve: Well, let’s talk about dB first of all and what acoustic panels don’t do. What the panels don’t do is change the source. So if a dog barks at a hundred dB, that’s what the dog will bark at. If a human shouts at 80 dB, that’s what they shout at, right? So the panels can’t change that.

Primacoustic: So how does an acoustic panel like the Primacoustic Broadway panel address this?

Steve: The panels will then absorb the sound after it leaves the source and will stop that sound from amplifying in the room through bouncing off of reflective surfaces or hard surfaces.

Primacoustic: Is this the same as soundproofing?

Steve: No, and this is something that people get very confused about, soundproofing versus absorption. Soundproofing is a very, very different discipline where you’re preventing sound energy from leaving a room and escaping into another room. Sound absorption is actually treating the acoustics within that room. So an absorption panel will not stop sound leaving the room. That’s a clear difference that a lot of people get very fairly mixed up about.

Primacoustic: How does this relate to addressing noise levels in public spaces?

Steve: So when we’re dealing with noise levels in places of public assembly, there are very clear guidelines in the United States, laid down by OSHA and laid down by workers’ compensation in Canada. Again, it’s not about the actual volume in the room. It’s the length of time that an individual is subject to that noise level. So again, we have to be very precise in what we’re doing.

What Can Sound Panels Do?

Primacoustic: So, back to the original question – what are acoustic panels designed primarily to do?

Steve: What the panels are designed to do is to take the sound energy and dissipate it into heat, stopping fresh reflections or stopping any reflections. They can be on the wall or they can be hanging from the ceiling or fixed to the ceiling. You just have to get the correct amount of absorption into that room to be able to bring the noise level down and to make that room a much calmer and stress-free environment, where you’re working, because ear fatigue is a major concern for people in the workplace.

Primacoustic: What impact does ear fatigue have?

Steve: It dilutes concentration. It can create stress. It will certainly be tiring. So one of the benefits of acoustically treating your room is that well-being component. In fact, I would venture to say that for Primacoustic, the well-being component has become much, much more important than just being a cool audio-video product. Also, because most acoustical panels are made nowadays with 40% recyclable fiberglass. It doesn’t take any electricity, doesn’t have to have a software upgrade. So it’s a very sustainable, almost old school product, that has got a new lease on life in this modern world.

Primacoustic: And so what’s the first step in addressing high sound pressure levels in a restaurant?

Steve: So what we have to do is we have to figure out what is the issue in the room, what is the room used for, and how are we going to fix it? So here’s kind of the rule of thumb. In the simplest terms, our panels all come one inch, 2-inch and 3-inch thick. We have some at one and a half inches. A 1-inch panel only has the frequency response for high frequencies, like the human voice. So you would only put that into a room where it was a lecture hall or a classroom, or a boardroom, or just somewhere where there’s really only speech. A 1-inch panel will take care of that.

Primacoustic: You mentioned the 2-inch panel. Talk a little more about that.

Steve: A 2-inch panel is really kind of the utility panel. It’s the one that we use most of the time because it has a much broader frequency response.

Primacoustic: What’s the most common use of a 2-inch panel?

Steve:: It would go into a church where there is a rock and roll service on a Sunday, where there are drums and there is bass and there is guitar, but there’s also a choir. So that’s where the 2-inch inch panel would go, into that environment where there’s also some … or a boardroom or an audio-video room where there is some playback, a mission-critical room, a first-response telephone center. Again, it is just speech attenuation, but there are the sounds going on and things like that.

Primacoustic: What about the 3-inch panel?

Steve: A 3-inch panel is very rarely used in the commercial world because it’s very aggressive. It starting to get down to very, very low frequencies. If you put it into a commercial room, it’s almost going to suck too much energy out of the room. 3-inch panels go into broadcast studios, radio studios, home recording studios and places like that.

Primacoustic: So the thickness of the panel matters.

Steve: Yes, the thickness of the panel is important. But what’s even more important than that is that you have to then work out what the correct percentage of absorption is for that room. If you don’t put in enough absorption, there’s not going to be enough panels there to actually fix the room. If you put in too many, the room is going to be dead. A dead room is almost as oppressive and unhealthy as a live room.

Primacoustic: How do you go about measuring the specs for what panels, and how many, to install?

Steve: We work off the overall square footage of the wall space of a room, which is the length, the width, and the height of the four walls. Sound is multidimensional, so you have to work out the whole wall space of the room. 10% of that would just be to treat speech attenuation as I said, classrooms or lecture rooms or things like that.

How Do You Measure Noise Levels in Restaurants?

Primacoustic: What about measuring for restaurants?

Steve: At 15% coverage you’re starting to get into restaurants where there is some music playback. They may have an acoustic guitar on a Saturday night. Very, very noisy, lots of excitable people in there, cutlery being banged and plates being banged and all the rest of it. So you’re getting up to around 15%, or a church that maybe just has a choir and an organ. At 20% you’re getting up into that church that has not contemporary service where you’ve got the drums and the bass going. Or you need that little bit more absorption so that the room will be slightly dead in something like a first response, call center or something like that. At 30%, you’re starting to get into home theater or some performance theater and a voice-over booth. Beyond the 30%, you’re getting into studios and broadcasting and radio and stuff like that. So it’s important that you get that right. It’s a very simple formula.

Primacoustic: Let’s get back to restaurants for a second. That is an important sector for acoustic panels, and one Primacoustic does a lot of work in.

Steve: When we started the company 10 years ago, we actually thought that getting into restaurants was going to be a natural evolution because the biggest complaint restaurants have is not about the service. It’s not the food. It’s the restaurant noise. And people will go, just leave and they’ll never come back because it’s too noisy. But if we go back 10 years, restaurant owners didn’t want to know about acoustic treatment. They just completely ignored it. Now here we are, 10 years later, and restaurants are now our biggest market, because they’ve woken up and realized that first of all, that on that Saturday night, they are probably breaking the OSHA regulations and leaving themselves open to an inspector coming in and giving them a citation. There’s not much you can actually do about the source, but for example, the permissible noise level exposure for the OSHA guidelines is eight hours. If you’re working eight hours, it can’t be above 90 DB. Six hours is 92 DB. Four hours is 95. Three hours is 97. Two hours is a 100 DB. I’ve been in restaurants when I’ve pulled out my dB meter and that restaurant is 100 dB. Now that waitress or the bartender, for example, is probably on an eight-hour shift. So not only is the restaurant contravening OSHA guidelines, but they’re also putting the well-being of the staff at risk.

Primacoustic: Talk a little more about why installing acoustic panels is important for the business owner of a restaurant.

Steve: If the room is treated, that’s going to be a very different working environment, because the waiter or waitress is going to be less fatigued at the end of the shift. They’re going to be less stressed. They’re going to hear with clarity when people are patrons are ordering or whatever. They’re just going to be a lot more healthy. So the big selling point for restaurants nowadays is the well-being of the patron as well as the well-being of all of the employees. Now, a restaurant falls into that 15%, 2-inch panel or 1.5-inch panel. So that is an area of where you’re reducing the overall ambient sound within that environment. You’re really doing a multitude of things. You’re making it a much better place for people to work and also it’s a much better dining experience for the individual or the couple who are looking to have a conversation over the dinner table and not be yelling and screaming and shouting.

Primacoustic: Is there a significant trend in restaurants starting to install acoustic panels for this reason?.

Steve: What we’ve found that’s happening now is that one restaurant in a locale goes and gets acoustically treated. Then the next thing we know there’s two or three others in that same area, because as the patrons are dining in the treated one, and then they leave and they go to a noisy restaurant the following week and say, “Hey, you guys need to do something about the noise like that Hot Cactus place down the road.” So a lot of them are being encouraged by diners into doing it.

Primacoustic: What role does a regulatory agency such as OSHA play in this process for restaurant owners and other businesses?

Steve: In the States, particularly more so than up here in Canada, restaurant owners are paying great attention to the OSHA audio guidelines, because the standard goes beyond restaurants. It goes into manufacturing plants, it goes into any place of public assembly where OSHA expects people to stick to these permissible noise levels.

Primacoustic: Are there reasons other than OSHA guidelines regarding why it makes sense for a business owner to consider installing acoustic panels?

Steve: The second part of this trend towards acoustic panels is the green sustainability part. The U.S. green building council, which has become a very powerful group of architects and engineers, have been promoting green sustainable buildings for a few years now. Most new constructions in the United States, especially schools, aspire to get this platinum or Gold LEED certification. So, for example, grass growing on the roof, solar panels, recyclable water. But now they’ve actually decided that how the room sounds is very important. Which, again, ties into the whole well-being component. And because it’s recyclable fiberglass that we’re using and there is no electricity or batteries or whatever, it is a product that actually brings now LEED certification points to a new project.

What Are Acoustic Clouds?

Primacoustic: Talk a little about acoustic clouds and sound absorption in the ceiling, and what benefits that has.

Steve: One of the things that is great about the acoustical panels, especially if you’re in a restaurant and you hang them with a cloud and the ceiling is black, you can paint these clouds black. And nobody actually knows they’re in the room. Nobody actually can see them. They’re not really interfering with the ascetics or the decor of the restaurant. They’re just hiding up there in the ceiling, quietly doing what they’re designed to do — to take that sound energy and dissipate it into heat.

Primacoustic: How much of the increased awareness by business owners is being driven by the OSHA guidelines and how much of that is being driven by restaurant owners just becoming more aware of the need for that level of absorption to help keep noise levels down, so their patrons are not at risk?

Steve: We haven’t done any research on the numbers or anything, but I think it’s a combination of both. I would say more so, it’s just the awareness of the owner of the restaurant, who is looking to give the staff a better working environment and to have their patrons dining in a much calmer atmosphere. I just think there’s been an overall improvement and awareness of what it acoustics can do to a room. We’ve also been quite active with restaurant associations. I think we had three or four articles published in a couple of their monthly publications, which was basically talking about the benefits of acoustically treating.

Primacoustic: Talk more about that. What impact has the restaurant associations had on the installation of acoustic panels?

Steve: I think the restaurant associations have kind of realized that this is just as important as some of the other things that restaurants need to do business. So that’s been a factor. But I do think perhaps what’s driven it more than anything has been public complaint. It is the number one cause of complaint in restaurants. I just think that it had gotten to the point where restaurateurs were losing business because it was so noisy.

Primacoustic: I think it was Zagat that provided consumer research showing consistently year over year the number one complaint in restaurants is not the service or the food – it’s the noise levels.

Steve: Yes. Zagat did the research and noise was the number one complaint was restaurant noise.

Primacoustic: Other than reverb, echo, and intelligibility, what other acoustic issues do you deal with that acoustic panels can solve.

Steve: Obviously bass is an issue as well. That’s a very different beast. It’s much more difficult to contain bass. That’s why we have bass traps and that’s why we have 3-inch panels. But in commercial, it’s really an issue. In fact, it’s really an issue even in churches, who are driving big subwoofers and bands like that. So there certainly is bass, and there’s also another discipline called diffusion. But once again, that really sticks to the high-end performance theaters or the broadcast or home theater or recording studios and things like that. In the main, in the commercial world, they’re really first reflections, echo, standing waves, reverberation, and bringing the volume down. These are the main reasons for doing it.

Primacoustic: Can installed acoustic panels have a negative impact in a room, say in a room that might not need sound absorption right now, but may in the future?

Steve: No. Because acoustic panels are very passive. They lie in wait, really, and wait to work until needed. They are designed to absorb the excess. And to keep that room calm. So if there are two people in a restaurant and they’re speaking quietly, the panels are still doing a little bit of absorption there, but it’s hardly anything. Right? But once you get up to 200 people in that room, then the panels get real busy. They’re then transferring much more sound energy into heat.

Primacoustic: Do acoustic cloud panels have a different purpose in the reduction of dB as opposed to the wall panels?

Steve: Acoustic clouds have a couple of advantages over wall panels, other than the aesthetics, where they’re kind of up there in the ceiling and nobody notices them and they’re quietly doing their thing. If they’re hung as clouds, then there’s a body of air behind each one. So you’re going to get better performance than you would from the wall panel, which actually doesn’t have a body of air. Now that means that the panel that’s hanging is absorbing sounds not only from the bottom but from the top as well. Whereas the wall panel is only absorbing on the fascia, right? Because it can’t absorb it from the wall side.

Primacoustic: What happens if acoustic panels such as a cloud panel setup are installed, and they don’t capture all of the acoustic issues such as reverb on the first reflection?

Steve: If the sound energy passes through the cloud and some of it is not dissipated into heat, it bounces off the ceiling and it comes back down and will do it a second time. So in effect, you’re getting much better performance, you’re getting more absorption and you would need, in the main, less clouds than you would need wall panels. Now you would think that a panel, let’s just say the panel accounts for one and then the cloud accounts for double absorption. It doesn’t really work out double absorption on the cloud, but one and a half times certainly would be a reasonable amount to say that each cloud gives you, as opposed to just thought one hit that the wall panel gives you.

Primacoustic: So it does perform better?

Steve: Yes, it really does perform better. Now when a wall panel performs a lot better than a cloud, for example, it’s not in a restaurant environment, but in a church for example, where you’ve got a rock and roll band on the stage and they’re driving out a good-sized sound system. That sound is just blasting off the stage and hitting the walls and the first reflections are just careening all over the place. You put these wall panels on the wall and it takes out these first reflections. So that’s where the wall panel really does earn its keep, where on the back wall, where there’s a slap coming off the back walls and stuff like that. So there is a place for both. In fact, in many instances, we’ll actually put in wall panels and clouds.

What Is Noise-Induced Hearing Loss?

Primacoustic: Let’s go back to the subject of NIHL, Noise-Induced Hearing Loss caused by high decibel audio. Does the potential damage from noise-induced hearing loss come from the reflection? Because if you can’t control the volume at this source as you said earlier, then is it the reflection off of the walls or floors that can contribute to the problem, and that’s something that sound absorption panels can help address?

Steve: Yes. One of the common mistakes that AV companies make is to throw more energy at the problem. So let’s go back to the church as an example. So the church has a bit of money to spend and their room is reprehensibly bad. There’s echo, reflection, I mean, it’s just a horrible place acoustically. No matter how many times our integrator or dealer tells them, “You’ve really got to treat the room infrastructure,” they’ll say, “No, no, no. We’re just going to install different speakers.” So they’ll put in more powerful speakers and all that’s done is just amplified the problem and the issue. So what people really should be focusing on is room infrastructure first and foremost. I realize that’s easy for us to say because we’re in the sound panels business. The trouble is that our 2 x 4 gray panel doesn’t have a USB port on it. It doesn’t have any flashing lights. It’s not a sexy product. So when people look at a nice new speaker system that they can hang, they’ll just think it looks really cool. Right? And then, they’ll look at our 2 x 4 gray panel and think, “I don’t want that because it doesn’t look cool.” Even though, without realizing it, the 2 x 4 panel is exactly what they need to address their sound issues!

Primacoustic: So education about what works, and what doesn’t work is important?

Steve: Yes, exactly! It’s all about education, education, education! We’ve got to try and get more people to understand the most important thing you can do in a room is look at the infrastructure first. Because, if you’ve got an acoustics problem and you hang more powerful speakers and loads of speakers to address it, that problem is just going to increase by 10% or 50% or more. So yes. The more energy that goes into that untreated room, the more damage that it’s going to cause.