Acoustic performance in WELL buildings
acoustic comfort / acoustic performance / sound design / WELL rating system / healthy building
WELL Certified / SOUND CONCEPT
acoustic performance with ethan bourdeau
Welcome to episode 48 of the Green & Healthy Places podcast in which we discuss the themes of wellbeing and sustainability in real estate.
I’m your host, Matt Morley of Biofilico Healthy Buildings and in this episode we’re in New York talking to Ethan Bourdeau, the Sound Concept Lead at the International WELL Building Institute (IWBI) - the organization behind the WELL healthy building rating system.
An architectural acoustician, Ethan also holds down a role as Executive Director of Standards and Built Environment for Quiet Parks International (QPI).
Ethan and I discuss the role of acoustics in creating a comfortable environment for building occupants; how pink noise can cover up unwanted background noise, sound zones and spatial layouts; the all important distinction between sound, silence, and noise; the role nature sounds can play in promoting wellness; and the main causes of noise in a building that need to be mitigated in a comprehensive healthy building acoustics plan in line with the WELL Sound concept he helped conceive.
acoustic performance / conversation highlights
Acoustics is just one element of a holistic platform of comfort metrics that are operating in synchronicity.
In WELL we look at spatial layout, acoustic thresholds and criteria for optimal performance (pulled from the leading acoustical standards) and in some cases, include novel requirements for acoustical design and acoustical comfort that have yet to really hit the market outside of the WELL rating system.
Not all sound is noise - sound is just sound until it annoys you, then it becomes noise!
WELL acoustic performance conversation with Ethan Bourdeau, Sound Concept Lead, International WELL Building Institute (IWBI)
full transcript courtesy of OTTER.AI (excuse any typos)
Matt Morley
Ethan, a pleasure to have you here. I'd like to start with some basics, if we may - what was your path into sound design and audio engineering? For people who are perhaps not entirely familiar with how that relates to real estate, perhaps you could give us a quick intro to that bridge between those worlds?
Ethan Bourdeau
Sure, thanks, Matt. It's great to be here. Happy to discuss this. So my background in acoustics and sound goes back to my days as a musician growing up. I've practiced and spent a lot of time performing on the folium, which is a low brass tube like instrument that carried me throughout a degree in Music Performance and Acoustical Engineering at the University of Hartford.
So, yeah, constantly listening to my own sound really led me to want to better understand the way that interior environments sounded and to what degree architects and designers have the ability to manipulate, shape and improve the sound of spaces that we spend our time in.
Nature sounds, quiet and wellbeing
Matt Morley
As context, the work you're doing with the Quiet Parks International (QPI) might give us a starting point of the best case scenario, as in a perfectly quiet, natural environment. Does nature provide a baseline of excellence in terms of sound and noise?
Ethan Bourdeau
My work with Quiet Parks International is my latest endeavor. It's been the result of a year's worth of collaboration with those folks, field recorders that have come together behind this one mission of preserving and recognizing quiet in the natural and built environments throughout the world.
Their expertise so far has brought them to places like Glacier National Park, Haleakala Crater on Hawaii, and various other urban and wilderness quiet parks throughout the world as potential candidates for meeting our criteria that denotes and best exemplifies what quiet really means to the surrounding or indeed visiting populations.
We have, over the past year, worked to define what that criteria looks like, how do we define quiet from a physical, a parametric and even a subjective standpoint.
To what degree do we assess using audio technology, sound level meters, audio recording devices, and even just anecdotal and colloquial evidence that we can get from people with boots on the ground in those areas to describe ‘quiet’.
Over time, we're planning to develop a better understanding of how quiet and the definition of silence and tranquility changes around the world. So we're actively recruiting and finding candidate spaces, including a site here in New York City, actually, that we're hoping can add more flavor to understanding and unraveling that narrative.
Nature sounds for wellness
Matt Morley
So these are areas where there's no obvious intervention of a built environment, you're effectively out in a completely isolated natural corner of the world, in which case ‘quiet’ is not necessarily ‘silence’ . It's the sounds of nature with no man-made interventions.
Ethan Bourdeau
It is, for the most part, we do find ourselves in instances where the term ‘silence’ could perhaps be the only classification in the case of some remote places like Haleakala crater, but you're right for the most part, we are entering places where the soundscape is defined by sources of sound that are not manmade, they are a part of the natural landscape, they could be geographical features, they could be animals, migratory birds, insects, etc.
Well Certified / SOUND CONCEPT
Acoustic comfort in buildings
Matt Morley
So if we then use that as a bridge into the discussion around interiors and buildings, the idea of acoustic comfort or acoustical comfort, do you see that as being a fundamentally objective measure? Or is it all to do with how each individual responds to noise and their personal reactions to whether it's too quiet or to silent or is it and then measures that you can use that would say, Well, this is the optimal acoustic comfort to perform a certain task.
Ethan Bourdeau
When we think about occupants within a space, we can learn a lot about where are those people are coming from if if they're entering a new office environment that's undergoing renovation, to what degree can their past and prior experiences with the acoustical quality or even just the indoor environmental quality of where they're originally used to, how does that inform the way that we as designers can approach facilitating better sounding spaces.
Acoustics is just one element of a holistic platform of comfort metrics that are operating in synchronicity.
Acoustics in the WELL Building Standard
I think one great example is how the WELL rating system has been able to break this down into the various concepts among which includes SOUND is a key feature.
In WELL we look at spatial layout, acoustic thresholds and criteria for optimal performance (pulled from the leading acoustical standards) and in some cases, include novel requirements for acoustical design and acoustical comfort that have yet to really hit the market outside of the WELL rating system.
It’s a huge opportunity, I think, for not just acousticians, but really architects, designers, folks who are consulting in the space of biophilic design to really ask those questions of what is it about the sonic environment that maybe even I don't quite fully understand or can convey to occupants in clients who are coming from those areas where that was a large concern and maybe an obstacle towards a better productive and more fulfilling workplace experience.
Possible sources of noise in a healthy building
Matt Morley
Okay, so what are the typical causes of unwanted noise in buildings be that an office, hotel, learning or residential environment? How does the WELL standard concept of sound mapping mitigate for those sources of noise?
Ethan Bourdeau
There are many different sources, for the purposes of an initial review of a building, we'll look at environmental impacts from exterior noise intrusion that can be sources such as traffic, aviation noise, pedestrian noise depending on where this place is located.
We also look at Interior mechanical systems design and the way that building services can potentially impact not just any one given space, but the building at large which introduces sound in a number of ways.
Sound can travel through air, it can can travel through vents in HVAC systems, even through structures. If you have large, rotating pieces of mechanical equipment that are delivering air throughout a building, or even filtration systems, the vibration of air and movement can enter the structure and then radiate throughout an entire building.
We can also talk about occupant generated noise in the office that can be as one of my friends likes to say, the person next to you with the Frito lays chip bag in the middle of the day making sounds while you're on one of your 100 Zoom calls for the week. Or it could just be any combination of activity that's happening again throughout the building.
So while sound travels through air it can also travel through structures and with the proliferation of fitness areas and CrossFit gyms, things like impact noise from weights can travel through an entire building as well. Those lead to distractions and other obstacles to productivity.
Sound mapping in a healthy building
Matt Morley
So the process of sound mapping then would be an attempt to prevent the construction of the eventual fit-out on a building project being completed before a plan is in place for acoustics.
So you're talking to the HVAC engineers, the architects, quite a few people around that table to try and get a sense of what the acoustic environment will be like in a space especially on a on a new build construction?
Ethan Bourdeau
So when it comes to acoustics, there's something that's generating the sound to the source, which can be controlled or maintained, in some instances, it gets a little difficult when we talk about occupants, for instance, but for mechanical noise or exterior noise intrusion, there's ways to investigate noise control at the source.
There's the path so what is between that source and the receiver with HVAC, we mentioned ductwork there's also structural components - are we reducing vibration caused by circular mechanical equipment.
In the case of occupant noise, what's blocking you from not just the line of sound or the the path of the sound, but also even the line of sight with you and another person that plays a role in what we call psycho acoustics or the role that acoustics plays in our own mental and cognitive, health and wellbeing within the built environment.
Then there's the receiver. And so that's us the listeners, the final crux in the acoustic comfort equation of - who is receiving this sound? How are they responding to it and then how can we qualitatively assess the subjective outcomes of such sound.
Not all sound is noise, sound is just sound until it annoys you, then that becomes noise!
Biophilic design and acoustic comfort
Matt Morley
That brings to mind a project that I was involved in, in Switzerland, it was a round shaped, concrete and glass corporate headquarter building for a natural food business. We were called in to assist both on the biophilic design side, but also trying to fix the incredible noise issues.
They had a lot of hard surfaces, double-height central atriums that were allowing sounds to bounce around from the ground level reception up to almost the second floor of the building. We looked at options for introducing acoustic materials and everything from acoustic paint on the walls to sound absorbing plant walls.
Noise control and sound absorbing solutions
I'd love to hear how you think about what the tools are available to a consultant in that type of environment, as a specialist really, in that type of thing, you're going into a space, they have a problem with noise, and it's already happening. What's in your toolbox?
Ethan Bourdeau
Well, the biggest question that I would ask at the start is the one that I hoped the project team would have asked before creating a space like this, it's what is it the intent of this space? Why are people congregating here? What exactly are the activities and the experiences that have happen happen in this particular environment, then from there we can define criteria.
We’d work with the team to say, unless you do this, you will not be able to achieve XYZ. So you know, in the case of this building that you're describing, it sounds like there could be issues with speech intelligibility, or potentially even issues with too much speech intelligibility, where there are areas where you want to hear someone speak, and you simply can't.
Then when you're working at your desk, you might be hearing more conversations than you would may like to, and so that's where we pull out the really specific solutions based examples for acoustic and interior design and noise control. So in these cases, we would look at how do we reduce the sound in that path equation that we were talking about and source path and receiver?
Speech intelligibility for acoustic comfort
How do we bolster speech reinforcement, if someone is giving a presentation if they're giving a lecture, or even if they're talking on a simple zoom call, we're now starting to add tools to our toolkit that address this.
This in this hybrid workplace lifestyle, where we can communicate with others around the world like you and I are right now and not necessarily need to be in a studio that has acoustic panels like mine, you can be in a place that considers speech intelligibility without really breaking the bank and creating something that's a studio quality space.
There's no one element of acoustic comfort that should be focused for every single project, every single project is different.
WELL Rating Standard on sound in open plan offices
Matt Morley
So the WELL rating standard is especially strong on mixed-use buildings, and particularly commercial office buildings. Imagine then an open plan, office space for a creative team, the intent was originally to foster collaboration but there has been kickback on that over recent years around productivity taking a hit rather than a boost. Do you think there's still space for open plan offices like that with certain acoustical interventions?
Ethan Bourdeau
So a hot topic in the acoustics industry, right now, I'm fortunate to sit on a few Working Group committees for ISO and other standards groups that are specifically looking at Interior acoustics in the open work plan environment. And these conversations get very complicated very quickly, because the culture of Open Office acoustics and open office use in general changes so much as you go into different regions throughout Europe, and especially between North America, Europe and the rest of the world.
Acoustics in a workplace wellness strategy
Where we pull this criteria from to develop, and design, better acoustics and open offices changes quite a bit. So what I like to do, again, is really take it back to some fundamental steps. And on a lot of these working group discussions, I bring up what I feel the WELL rating system has done so well in breaking down into the fundamentals of what types of zones could you potentially think about, and what are the lowest common denominators for acoustical comfort when thinking about spatial layout, from a workplace strategy perspective in an open office.
Acoustic zones in a healthy building plan
So we have a few categories in this WELL feature. So one, we break it down into quiet zones, where focused work is the priority, or that could also include places like bedrooms, for instance, what is an area that you want to protect in terms of acoustic comfort and make entry as a sensitive space, we then have mixed zones, which could be a combination of any of those things and include collaboration, not all collaboration necessarily has to be boisterous and loud and, and people shouting over a desk of a floor plans, or, or whatever, it could also just be, hey, we're going to meet together as a team in this open environment and discuss XYZ amongst ourselves at appropriate levels.
Then we have loud zones. And so these could be any combination of areas where you have noisy mechanical equipment that just needs its own isolated, dedicated space to be moved away from any other sensitive environments, are these gonna be places where you have amplified speech, you have maybe a very active teleconference room that uses amplification. So these are areas that you really need to keep separate from your quiet zones.
In the precondition, this is required for every single project in the sound concept. Now, we have found that when people approach from this lens they have a better idea of WELL, I know now what I should probably be pursuing with our subsequent optimizations in the wall rating system.
Spatial layouts in the WELL SOUND concept
Based on the spatial layout that we were required to do. I know that speech reinforcement is going to be important. I know that speech privacy in my Open Office is going to be important. So what do I need to do to then show up and make sure I'm meeting those needs for my occupants? And those conversations become very fruitful, we learn a lot more about acoustics than we would if we were just meeting criteria. If we were just submitting documentation, saying, from an acoustician, you pass, here's the checkmark. Here's the check in that box of acoustic comfort.
So I would encourage folks who are in that position of rethinking the Open Office, from an acoustic perspective to really focus on the lowest common denominator, how many spaces do you intend to have there where focused quiet work is a key function of the holistic open office design, and start from there, because if collaboration is the leading draw to creating an open collaborative space, the folks who rely on quiet zones to complete their work aren't being there. The folks that are relying on quiet zones to achieve their work, have needs that aren't being met by the design team and the organization who put collaboration first, when in reality, people want a healthy balance of both.
Sound masking systems in a healthy building
Matt Morley
And we also mentioned the idea of sound masking systems - the idea of there being a level of white noise that can be pumped into the background to create a baseline that can help cover some of the mechanical systems. How does that work? Is that about the frequency? Is that about the the intensity of the sound? And would some nature sounds fit into that category?
Ethan Bourdeau
Yes, so sound masking is a very tried and true technology that as a consultant, I've been able to deploy quite a bit in open office settings with great success. And what it really focuses on is delivering a Pink Noise signal, which is somewhat calmer than white noise, which, if you were able to compare the two on YouTube I guarantee you will have a preference over over pink noise to over white.
Why we choose pink noise is because you can you can also go into the sound source itself and adjust the contour of the equalization curve, so that it can really match and really perform in accordance with preferred occupant acoustic comfort parameters. Now that's that's more of the technical side of how you would deploy a system like this.
A sound masking system is a network of loudspeakers that are directly mounted hung from or otherwise located throughout a ceiling, plane or even plenum, they can be directly exposed or be behind an acoustic ceiling tile. So it's a very useful tool when we try to address speech privacy from a signal to noise perspective.
Sound masking for productivity in an office
Signal to Noise - meaning you have a ‘signal’, which could be another person talking, their voice carries throughout an office that you don't necessarily need to hear. And then ‘noise’ being what is the background sound level that allows you to discern that signal or the sound of another person's voice.
So as we raise that background sound, the difference between the ambient level and the signal is then reduced. And so that helps with reducing the total impact of hearing another person's voice encroaching on your ability to focus and be better productive in a in a workplace.
Natural soundscapes in the built environment
Now to your other question about natural sounds as a sound source, I'm, as a designer and in working with folks who are field recordists and who are architectural designers. I'm actively trying to indicate that introducing natural soundscapes into the built environment is a new format of introduced sound. Sound masking is a form of introducing sound that focuses specifically on speech privacy.
Natural soundscapes have a number of potential benefits to them as well being immersed in and hearing soundscapes of birds, wind, waves, etc. In a spatially uniform environment that can elicit emotional response in ways that addressing speech privacy, for instance, isn't necessarily going to do.
There's some really tremendous examples of new technology that's emerging that focuses on this. There's actually a company there's a couple companies one is MoodSonic, who actually sits on our advisory board for the sound concept that focuses on delivering soundscapes from a natural sound source perspective.
There's a new company that I've heard about called spatial, who I'm trying to learn more about in the coming weeks that is providing a similar solution and has worked with some hospitals and then North America to create spaces for respite for nurses and people who need a moment of Zen or peace or tranquility to to continue their daily work.
Biophilic sounds for wellbeing
Matt Morley
Yeah, I've certainly used it in an intimate nature space in the central business district of London called Canary Wharf. We did a month-long biophilic design research study.
Sound was definitely part of what he called a multi-sensory wellbeing design strategy along with aromatherapy, and smart lights and various other things. But I found it was all too easy to just accept that, you know, a Spotify playlist of English bird songs, as we were in England, would be sufficient, I felt that there was more to be done in terms of perhaps matching place, season and the situation or the desired emotional response. And so I could see how those type of services could perhaps add that extra layer of detail, right?
Ethan Bourdeau
In reality, the ear is not dumb. The ear knows when it's in an office and crickets are playing from a Sonos speaker in the corner. The brain understands that when it is truly immersed in an environment, only then can it naturally respond and react to it the way that we would if we were there in reality.
I am an aspiring audio engineer and more of an architectural acoustician. But audio engineers are really looking at this from the perspective of, of how do sounds really travel in the sound field? And how can multiple loudspeakers and an array of loudspeakers help to create and elicit those environments.
I've seen examples where in software, they can create sound sources and an XYZ grid and just have them move around. And you know, not too dissimilar to going to the theater and listening to a Dolby system where you can pinpoint exactly where the sound is in the given cinema. So we're seeing that enter places like workplaces, hospitals and public public areas where sound installations can better interact with humans and vice versa.
WELL Rating System on SOUND
Matt Morley
In terms of how the WELL rating system positions the sound concept, the ultimate aim here, when you get all of this right, is primarily a boost in comfort and productivity, worker happiness? What are your desired outcomes in terms of a healthy building strategy and the acoustic component in particular?
Ethan Bourdeau
It changes per project type. So in a typical workplace, yes, we would talk about workplace satisfaction, we've talked about productivity, we would talk about ability to collaborate, if if there are more spaces, if there are more areas throughout a given office floor plate, where a person can interact with different types of acoustic environments to better support their work, there is a sense of fulfillment that we can we can draw from that and indices indicating surveys that are indicating that noise is a top concern.
Or pointing to that the lack of choice and the inability to be in a place where you can speak when you need to without worrying about other people hearing you or vice versa.
That is the primary focus that is that is something in the workplace environment that that is a key outcome. Absolutely. And especially now when we think about how do we return to that type of environment where you you are looking someone directly in the eye from across a table and your voice doesn't have to go through a series of digital signal processing through Whatever you can describe the software for this hybrid environment, I think there is a real learning that we will have to undertake when it comes to thinking about how we communicate in the workplace, for instance, and then that will ultimately describe the way that we address acoustics from the onset and design.
Acoustics for improved sleep in residential and healthcare
Now, with places like healthcare and residential, we see noise as a concern as it relates to sleep. And with acoustics being a top contributor to sleep disturbance, it's important that we can see the key outcomes in things like fitness trackers, and other types of technology that can measure and better assess our quality of sleep.
This is very important with healthcare where patient surveys that are administered, especially here in North America, indicate the performance of a hospital based on a patient's ability to sleep and spend their time recovering in some instances.
The links between acoustic comfort and patient recovery are many, it's actually where a lot of the research in acoustics and health and wellbeing derives from.
So over time, as we see places like hospitals, Senior Living outpatient facilities, adopting more of these health and wellbeing metrics into their design, the more we're going to see these uptakes in patient satisfaction surveys.
Matt Morley
In summary then, the WELL rating standard for me is a such a helpful marker it has given me at least a minimal level of understanding in sound and acoustics planning. So congratulations on everything you've done so far. How can people reach out to connect with you?
Ethan Bourdeau
You can find me on LinkedIn of all places. I'm usually posting the latest updates with all of the outfits that I'm involved with there.