modulyss Talks - Innovations and technologies in Acoustics with Julian Treasure
Hi good day everyone and a warm welcome to another session of modulyss Talks. I'm Sophie, your host for today's webinar. Today marks the second part of our three-part series on acoustics and we are privileged to have Julian Treasure with us. He's a five times TED Talk speaker with over 150 million views and author of two books: 'The Sound Business' and 'How to be heard'. As the founder of 'The Sound Agency', he is our expert to guide us in shaping sound environments for commercial spaces. So without further ado, let's extend our warm welcome to Julian and hear from him.
Well, thank you very much indeed and I'm delighted to be speaking to this august gathering. Today, we'll be focusing on the power of sound to affect something, you probably come across a great deal: indoor environmental quality. Let me move myself down here out of the way. IEQ. Sound effects it for good or for ill and we'll be looking at some of the innovative ways that you can use it to the benefit of those in the spaces you design. Let's start by thinking about what IEQ really means I have one definition. It's an environment that supports and enhances people's happiness,
effectiveness and well-being. Drill down into each of these three key goals and you get some pretty useful targets to aim for I think. What promotes happiness? Research suggests that connectedness to other people is a prime mover along with being comfortable in a safe high quality environment, where you have some say in how things happen and especially over your privacy. What about effectiveness? Well, that requires clear communication, the right tools being available and being able to concentrate.
It also demands an environment that's flexible enough to offer different working spaces and to cater for diverse people including neurodiverse people of course. And finally well-being. Cleanliness of the space and the air are high on the list especially after Covid and of course posture and the right lighting of vital and as we'll see sound plays a major role here too. In fact most of these things operate in all five senses, not just for the eyes. So today we're going to focus on designing for the ears because sound affects you, me and every human being.
The whole reason we need the science of acoustics is this power that sound has to change the way we feel, think and behave. Let's start with a crucial distinction because sound is not the enemy in this story like fire, water or money, sound can be a great force for good or it can bring about terrible harm. We call bad sound: noise that can be a purely personal, subjective term but here we're using it to describe all harmful or unproductive sound. For good or ill, sound affects us all in four powerful ways. The first is physiologically, sound is constantly altering your body's rhythms and autonomous systems any sudden or unexplained noise possibly like this... Sorry about that, triggers your fight flight response giving you a shot of cortisol raising your heart and breathing rates, if your alarm clock sounds like that I do recommend you to change it.
By contrast a peaceful sound like this... will lower your heart rate and reduce stress very effective if you have insomnia or anxiety. Sustained exposure to even moderate noise has multiple damaging outcomes for health but sound can equally enhance well-being. It can lower blood pressure, boost immunoglobulin which protects against infection and even reduce experienced pain.
By the way musical training has been shown to enhance verbal memory, special reasoning, speech processing and literacy skills to the point where musicians actually have bigger brains than non-musicians. The second way sound affects us, is our feelings the opposite example is music which Hermann Hesse described as time made aesthetically perceptible. Music is emotion in sound which may be why it's a universal human trait.
No tribe has ever been discovered that hasn't developed music. Let me share with you one of my favorite sounds which is a short intense musical sound that I think you'll find creates a powerful, emotional response if you're wearing headphones and you hear it well it's the wonderful Sonic logo of THX. Here it is. That one gives me goosebumps every time, I hope you felt something too as that build. But music's not the only kind of sound that can change our feelings. Over hundreds of thousands of years we've learned that when the birds are happily singing all is usually well.
So bird song generally makes people feel safe, it's also nature's alarm clock so it's a very natural way to wake up in the morning and a great sound to work to as it encourages mental alertness. Many other sounds can generate positive emotions perhaps the sound of your baby laughing or many people love the sound of a distant thunderstorm. But sound can also create negative emotions. Noise often leads to anxiety, anger and at least discomfort
and in either case volume is always an intensifier loud sound, loud music can induce if euphoria for example while violence is usually accompanied by shouting another loud noise. The third effect of sound is on cognition, you can't understand two people talking at the same time in this case one person talking twice you can't do it, can you? We have bandwidth for around 1.6 human conversations. We're programmed to decode language and we have no ear lids so in open plan offices other people's conversation takes up one of our 1.6, displacing our ability to listen to the voice in our head that we need when we're writing, thinking or calculating.
That's why noise like this is the number one issue in offices. Research shows that it can cut productivity for knowledge workers by as much as two thirds, so sound can boost or destroy our productivity by affecting our concentration, energy levels and motivation. The fourth and final effect of sound is that it changes what we do, our behavior. From a wealth of research in the retail industry we know that fast-paced sound speeds up, chewing in restaurants and walking in stores which means we leave sooner and spend less.
Loud music increases drink purchasing. Noise in offices has been proven to make people less helpful. And noise is generally associated with anti-social and even agressive behaviour. Even unnoticed sound can dramatically change what we choose to buy, which is why I'm showing a bottle of wine here. It illustrates a stunning piece of research where scientists tested the power of sound and the behaviour in the supermarket selling French and German wine, with identical visual displays. Day by day over several weeks, they alternated a little bit of this..
with a little bit of this... So what happened on the French music days, French wine outsold German wines by five bottles to one, which may not be too surprising. But on the German music days, German wine outsold French by two bottles to one. That's a huge shift in behaviour and significantly when asked most people had not even noticed the music, so the effect was entirely subconscious. Well if that's how powerfully sound can affect my behaviour, yours and that of the people in the spaces you design, we really do need to start designing with and for the ears as well as the eyes. And there are many examples of the senses interrelating. For those of
you who design restaurants, this one's interesting. Noise like this as well as leaving us with a sore throat and a sore head after our meal, also degrades our ability to taste food especially sugar and salt. Restaurateurs need to understand that buzz and noise are not the same, you can have a quiet buzz. If you carefully create congruent design in all five senses you get a thing called 'super additivity'. In the world of super additivity 1 + 1 doesn't equal two, it can be many times more than that. The aim is to have all the senses pointing in the same direction, reinforcing the same message, creating the same mood or supporting the same activity.
But as we've seen noise is a serious issue, it's one that's widely ignored because most people have gone numb to the effects of sound on them. Nevertheless, effect it does have, as we've seen. Noise is ranked actually just behind air pollution as a killer. The amount of noise is increasing in line with the human population of course but sadly nowhere is it a political issue, you won't hear a politician saying: "Vote for me. I'll make it quieter." The World Health Organization estimates 5% of the world's population, that's roughly 400 million people, have disabling hearing loss and the forecast is that's going to rise to 1 in 10 people by 2050.
Noise damage impacts our health more generally than just our hearing though. Chronic noise exposure is associated with heart disease, breast cancer, respiratory disease, cognitive decline, all sorts of illnesses. It reduces life expectancy. In Europe the estimate is up to 1.6 million disability adjusted life years every year lost to noise, that equates to around a day of life lost every year for every person in Europe. And there's pure economic costs, massive of course where people have lost sleep, they make mistakes, they have accidents, arguments, conflict and so forth. The biggest estimate I've seen or the best estimate recently I've seen of the financial cost for Europe was something in the region of 38 billion euros a year.
Many of these effects occur in residential spaces of course and that's not really what we're focusing on today, I think we're focusing more on noise in three working environments. Offices, healthcare and education and that narrows the damage down to these five things which I think you'll agree are all intimately linked to happiness, effectiveness and well-being, in other words IEQ. Noise, frankly, is an IEQ killer. Let's start in offices, all those hard surfaces are going to make this room very noisy when occupied and the parallel reflective walls, ceiling and floor will create unpleasant resonances.
So that room is going to have a lot of negative effects on the people working in it. And here's a list of them. But remember these negative effects can be reversed. So with those things going on, it's no surprise that noise has been the number one complaint in offices for a long time. The center for the built environment in the US published the collected results of surveys completed over 20 years by over 90.000 respondents in 900 buildings. Lack of sound privacy was the leading irritant by some distance and two of the top three problems are sound related.
The Leesman Index, which I'm sure many of you have come across, has surveyed over 800.000 responses in 5.700 buildings worldwide. So it asks: 'How important are these features of your office to you and how satisfied are you with them?' Well the gray bars show the proportion rating lack of noise and provision of quiet working space as important, it's very high ratings. But the red bars show how satisfied people are and these gaps are the biggest on the whole Leesman Index.
These are important things and people are unhappy with them. So as I said you can reverse them you know if we design the right sound in an office, we can reduce stress, enhance communication, help people to concentrate, reduce errors and accidents, give people more job satisfaction, help them to be more productive. What about education? We focus a lot on sending education, don't we? How good is the curriculum? How effective are the teachers? But hardly at all on receiving it can the students actually hear the education? How hard are they having to work to hear it? Well here's another room I'm showing with hard parallel surfaces, average noise levels in classrooms like these regularly reach 65 dB which is incidentally the threshold at which long-term exposure increases risk of heart attack.
Well that means that teachers may well be shortening their lives by working in such spaces. Let me demonstrate the effect of poor acoustic design like this on comprehension, so what you're about to hear is a simulation where a teacher is speaking against moderate background noise in a classroom. Let's start it with a reverberation time of 1.2 seconds. I think students would be working very hard to understand that day after day, wouldn't they? So let's take it down to one 0.8 seconds reverberation time, exactly the same sound
source and background noise. That's much better but we can go further still take it down to 0.4 seconds which is recommended for meeting rooms, classrooms and so forth really the speech intelligibility becomes excellent and all of the students will hear all of their education. It sounds like this. So that's the same sound file in three different reverberation time rooms. It's not just the noise of talking movement in equipment, the external noise of course can intrude.
Studies have shown that a 5 dB increase in school aircraft noise exposure, leads to an average delay of 1 to 2 months in reading ability. Whatever the source, noise in schools is damaging the outcomes and the well-being in those places. But as with offices, if we design really good sound there are so many benefits that we can achieve. And finally let's look at healthcare. Florence Nightingale said this over a hundred years ago but sadly we didn't listen. Noise in hospitals has been measured at 12 times The World Health Organization recommended maximum level by day and eight times too high by night.
I carried out a sound audit in one major US hospital and to be honest cacophony would not be too strong a word. Hospital noise sources are things like alarms, many of them of course unnecessary and completely ignored. Alarm fatigue is a well-known phenomenon in hospitals and equipment hisses, beeps, buzzes and so forth as well as people talking, moving and even shouting to one other impatient spaces and all of this is made worse by the acoustics. Again we typically have parallel hard surfaces, because cleaning is very important in hospitals, bouncing sound around. So it's no surprise that in the US there's a measure of patient satisfaction called HCAHPS and it shows that noise is the number one complaint in hospitals and has been for a long time.
Quietness has had the lowest satisfaction score on the survey for years and years. Well that's the damage to patient satisfaction but that's not the only casualty of noise, mainly by increasing stress and compromising sleep. Hospital noise lengthens recovery times and makes the experience of hospital more unpleasant and less healthy. In these days of critical bed shortages this is particularly a shame, I think, and I honestly believe we could transform healthcare outcomes almost overnight simply by improving the acoustics in those spaces and then of course we reverse negative to positive and turn sound into an ally instead of an enemy.
Numerous experiments have shown that well-designed sound can create many beneficial outcomes in hospitals from reducing stress in waiting rooms or pre-op beds to speeding up recovery post procedure. So what can you guys do about all this noise? I'm happy to say the answer is: a great deal. You have a powerful toolkit that allows you to design environments that will promote or produce beneficial sound instead of harmful noise. It starts with site selection, ensuring wherever you can that critical buildings like schools and hospitals are far away from harmful noise sources, like airports or factories.
Next there's planning the Sonic Journey, especially on entering a building it's becoming more common to have transition spaces. They're often used in art galleries and now being used in schools and other places to help people adjust from a noisy street as they head into a focused work or healing environment. And then very importantly there's room geometry, steering clear of parallel hard surfaces leading designers are now using trapezoidal geometries for conference rooms for example especially where hybrid meetings are common. But for the rest of this talk I'm going to focus on the second set of tools the acoustic tools which underpin all sound in built space, noise control and designing healthy productive soundscapes. Let's start with the foundation of all good sound acoustics. Now you're probably thinking: "Oh no, we need acoustic ceilings everywhere so the world's going to look like this", but I have news for you.
There's been a revolution in acoustic materials. No longer does acoustic performance mean kissing goodbye to aesthetics. A whole range of new products are both acoustically effective and beautiful to look at. I call this acousthetics.
Apologies for the neo logo, the new word but I think it sums up what we'd be looking at. Let me show you some examples. Today you can get created with ceiling tiles, they don't have to be just oblong or square and with lighting as well I mean this is a suspended ceiling but I think that's really beautiful, don't you? You can use metal.
This metal ceiling has got custom perforations and it becomes acoustical if you add infill panels behind. And wood can sound just as good as it looks, this is an acoustical ceiling, again you can see perforations and gaps between and there's acoustic material behind. And even this amazing wood treatment is acoustical, it's micro perforated, barely visible to the human eye and it yields excellent acoustic performance. Here are those tiny perforations that you can see, again with acoustic material behind. Even exposed structure ceilings. They're not a huge problem because we can hang things from them that look amazing.
You can have good sound and great visual design by using baffles like these or blades like these. And you can also stick acoustic material directly to a concrete ceiling. Imagine how reverberant this space would be without the acoustic panels on the ceiling which are applied directly to the concrete. And of course we all love the look of plaster board. It's clean and elegant, well now you can install ceilings that look like plaster board and yet effectively absorb and block noise. This is an acoustic ceiling. So here's a live example, this is the American Society of Interior Designers, headquarters in Washington DC.
ASID has installed biophilia and we'll come on to talking a little bit more about biophilia in a moment. Biophilia is bringing the outdoor indoors, I'm sure you all familiar with it's an important movement now in architecture to reconnect us with nature and to get away from the sense of being in a hermetically sealed artificial environment. They've also installed a lighting system that is sensitive to circadian rhythms and that's an important thing to take into account when we're designing spaces. The whole office was designed to meet the WELL Building Standard and I'm a sound concept adviser to the WELL IWBI, the WELL Building Standard and they're doing a huge amount now to consider people's well-being and the effect of sound and acoustics on that.
So in critical areas throughout this office the architects, I think that was Perkins and Will, they used ceiling tiles combining absorption and blocking, for example in this meeting room, to achieve excellent speech intelligibility as well as privacy. Because you don't want people out outside the room hearing private meetings inside it and it was all very sustainable as well. So that's a word on acoustic treatments which are now so exciting there's so much you can do with them and they can look just as gorgeous as they sound. Let's move on to noise control because even if you get perfect acoustics, you'll still need to avoid unnecessary noise.
You're obviously not in control of the main noise sources in offices, schools and hospitals, that's people. But you can design for a low noise floor, that's the sound in a space when it's operational but there's nobody there, and you can do that by specifying quiet equipment. Especially things like HVAC and by ensuring that any large machinery doesn't create resonances or vibrations in the structure.
I don't know about you, I've stayed in so many hotels, I'm the person who goes out into the corridor and unplugs the ice machine which is zooming just outside my door and I've also been in places where the whole room is trembling because of the HVAC plant on the roof. If you're involved in any interior design, please try and avoid sonic disasters like the worst one I come across: metal furniture on cement floors, I've encountered that in catering spaces, particularly every time somebody moves a chair the noise is horrendous. So think carefully about things like that, glides on chair and table legs don't cost much but they really transform spaces and also space planning to ensure that in a layout like this the noisy people that's the red team over there don't disturb those who need peace and quiet to work.
If possible always create a range of spaces with different acoustic characteristics to support different types of working and of course different types of people. And finally try and make blocking sound a habit especially in ceilings because you never know how a space will be repurposed. It's very often the case that a building is designed one way and then used in different ways in the future you never know when privacy is important and if we have a relatively transparent ceiling sat on top of walls with a gap up to the concrete sound will just jump over the top and that means you'll be able to hear what people in the next office are doing if you use a blocking ceiling throughout you avoid that problem and give the client a future proof building. So we've got the acoustics right, we've controlled the noise now we can get creative. Thinking carefully about any sound you might want to input into the space to enhance IEQ, boosting people's happiness, effectiveness or well-being or all three even.
Well research shows us the best place to look is in nature. Biophilia is reconnecting people in buildings with the nature outside and it works just as well in sound as with other senses. Bird song, we've already talked about, gentle breeze and gentle flowing water.
These are all lovely sounds that can help mask unwanted conversation whilst also bringing great health benefits for example by reducing stress and fatigue. A couple of years ago I was involved in the launch of a new concept in noise masking. Instead of mechanical noise, which is now being found to be tiring and even stressful, moodsonic uses biophilic or nature-based sound both to mask and to improve well-being. Moodsonic system involves a computer-based soundscape generator which produces sound in real-time that is to say it's not loops, nature doesn't loop nor does Moodsonic, it's algorithmic, created in real-time, everchanging just like nature and it plays through any suitable audio system the Moodsonic Insight Edge Sensors can be installed throughout a building and they monitor and change the characteristics of the sound in every space, matching it to the usage of that space so it makes the whole building smart, responsive to occupancy and use and it allows people also to spot where the quietest or loudest places are right now. So if you're looking for a quiet place to work that office on the fifth floor is currently very quiet and a user interface on a tablet allows designated people to control and change the sound at the touch of a button.
So this very wonderful biophilic based generative sound has found a very big audience, clients around the world include Microsoft, Steelcase, Elevance Health in the US, just a few examples of this approach in action. This is SAP's very biophilic Tokyo office. Moodsonic designed a soundscape based on the Japanese concept of Kokoro which draws together heart, mind and spirit. And that soundscape or those soundscapes use the sounds of Japanese nature as well as some tuned sounds from local instruments.
SAP Tokyo's employees say that Moodsonic makes coming to the office worthwhile that's how powerful sound can be. GSK offices around the world use Moodsonic to enhance both well-being and productivity and if any of you are in Dubai, you can pop into a new showcase for industry professionals in the offices of lighting and acoustic specialist aculite. Well, let's summarize. You have an amazing tool to help create excellent IEQ. It's the power of sound delivered through appropriate acoustics which can look wonderful as well as good, careful noise control and creative soundscaping.
Right now in so many spaces noise is damaging IEQ, it's making people sick, unproductive and unhappy. Well let's change that. We have to because workspaces are not going to go back to where they were 10 years ago. With the new emphasis on quality, this lovely room I'm showing you
here it could be in an office, it could be in a hospital, could be in a school wherever it is this is the standard we need to be aiming for because experience is everything now. As workplace guru & professor Jeremy Myerson says in this quote: "Work is an experience." Tim Oldman, the CEO of the Leesman Index has a much shorter description of the future of the workspace which I think sums it up pretty nicely. So what are the key aspects of working spaces of the future.
Whether it's an office, a health care location or an educational institution. Here's my selection of the targets we need to be aiming for. The last one recognizes the fact that we experience the world and our workplace in five senses, not just one. And it aims to create congruent design in all of them. So to close, here is a multi sensory breakdown of IEQ for you to think about.
These are some experiential design tools that you might use that profoundly affect IEQ. Of course you're very used to designing the visual aspects of spaces but the other four main senses can also powerfully affect people's experience of any workspace. And on top of the five senses we should add hearts and minds.
Research has shown that giving people privacy and some control over their space really enhances their satisfaction while safety is of course now a prime concern as we attract people back from WFH. And for maximum productivity we need to create and let people choose different environments that match different work and diverse people too. Well the focus has been on the sound of IEQ today which is underpinned by careful acoustic design, noise control and creative soundscaping. I hope that in this short talk I've been able to show you what a massive part sound does in fact play in determining IEQ, historically I have to say mainly in a bad way but in future what a powerful ally it can be for enhancing IEQ.
All we have to do is start designing with our ears as well as our eyes. Well I want to thank you very much for your attention and your ears today and I believe now we have a little time for some questions. Thank you so much Julian. This was really a very interesting presentation and I agree we should all start designing with the ears as well.
So as you have mentioned to the entire audience we still have some time for questions. You can put your question in the private chat that you see at the right top. We have already received some very positive feedback, it has been a great webinar for the audience as well. Let's see here. So first question: 'What are some innovative approaches, you suggest for transcending traditional norms in architectural acoustics?' Well I think the materials that I've shown really do open the door to a whole new way of thinking about acoustic design.
It doesn't have to be be prosaic, boring, ugly, it can be beautiful. I think we also certainly need to think about sound systems as an important element for most spaces. You know given that for example restful sound could transform outcomes in hospitals, well how do we deliver that to patients? Hospitals generally won't have a sound system or if they do like many commercial spaces, it's just like a safety system it's a PAVA which is designed for alarm calls or maybe emergency evacuation. And the spec is very low. So many times I've seen sound systems get value engineered out if anybody puts a good sound system in at some point somebody says do we really need $100 loudspeaker, no we can get something we can do $10 loud speakers and you end up in shopping malls, in shops, in, if offices have them, you end up with very cheap and unpleasant sounding sound systems. So I mean that's something also to think about the value of sound and the importance of quality of the sound that we deliver not distorted, not a tiny frequency bandwidth, not buzzing and so forth but a sound that reflects the quality of the rest of the environment and as I said at the end I think quality is key. It's what all the office experts are saying now in terms of offices if we're going to attract people back, then we have to deliver a much better experience than we ever did before and that's for the ears as well as the eyes.
Okay, thank you. Another question is: 'What do you think the role of music is in this?' I'm a musician, I love music but music is also the most abused sound of all. There is independent research indicating that a third of the population hate pipe music, a third like it and a third don't care. Well upsetting a third of your customers in retail is pretty serious, so we need to think quite carefully about what's appropriate.
And that's the most important word, you know I talked about congruence before, if you're in an office it may be that a creative team for example in an advertising agency love to have music on, they love to have some sort of creative stimulus because creative input tends to help creative output. But if the account handling team is right next to them working feverishly on a presentation they've got to give tomorrow morning, they are going to be going mad because the music is going to be distracting and disturbing them. So we have to think carefully about the sound and that's where I think again biophilic sound is very powerful because not many people object to it and certainly Moodsonic's experience is that if you involve people in the decision and give them some choice in the sound, they buy into it very readily and they enjoy it pretty much anytime if you impose sound on people without asking them they're going to resent it and that's particularly true of music music is a very distracting sound. Many people put headphones on to block out office noise but they play music, which is just as distracting, it's more fun, more enjoyable but it's just as distracting as other people's conversation because music is designed to be listened to, most of it.
I mean you might be able to find some very ambient or repetitive music which isn't going to distract too much but anything that changes that's not constant, is a distraction generally so I would be very careful about applying music without thinking clearly about the people in the space, what they're trying to do, the acoustics, the sound system, is it all appropriate and are you helping or hindering people with what they're trying to do. Very clear. Questions are still coming in. An interesting one. 'How will artificial intelligence affect this industry? Will it hurt or help?' It's gonna be fascinating actually, I don't know if you guys have come across the latest development Sunn O for example is an AI music creating force that's doing the same for music as AI is doing for writing text.
And it's quite good and it's only a first generation really. So we're moving on very quickly it's not beyond... it's pretty likely that within a couple of years we'll have AI tools that can create music that's entirely appropriate space by space or sound. So I'm sure it will come along, I'm sure we're going to be using and if we, after all AI is generally only is whatever we put into it but, if we brief it properly on the people, the space, the acoustics, the sound system, the needs, the used cases and so forth the timings then it's quite possible that we can have a whole building where the soundscape in each room is being controlled by AI and is sensitive to what people want in that space so it's going to be fascinating I have to say.
Let's have a final question, because we're going near the end of the webinar. 'You mentioned the sonic journey of space, do you think that architects can or will eventually play a greater role in designing the acoustics of spaces thus reducing the need for artificial acoustic treatments?" I don't see the distinction there, I think acoustic treatments aren't artificial they're fairly natural and I mean if you mean that you are going to build buildings which sound good without having anything put into them afterwards, yes please. There's something that should be thought about at the beginning, typically the life of an acoustician is not wonderful because they get brought in when there's a problem with a built space and there's no money left to deal with it so can you make this sound nice but we can't afford to pay you very much, that's not a very nice existence. They'd have a lovely time if you brought them in at the beginning and said help us to design something that sounds gorgeous.
Now they only get that really when you're talking about concert halls or auditoria or places like that where sound is obviously very important. I would say bring in an acoustician at the beginning and then you can design the acoustic treatments into the building in the first place so they become just a seamless part of an organic whole which is designed for all the senses congruently and designed to enhance people's happiness, effectiveness and well-being without having to go in later and put other things in if that's I think what the question was about and I think that's a wonderful approach. Yes and I think it was also a wonderful answer and also to end this webinar, so thank you again Julian for such valuable insights. So detailed information about today's talk, including the access to the recording of this talk, will be sent to you via e-mail and looking forward we're thrilled to announce our next webinar on acoustics featuring Émilie Carayol, she's an esteem acoustician at Khale Acoustics, who will be presenting some intriguing case studies. So thank you all for joining us and we look forward to seeing you in our next modulyss Talks. Bye.
2024-04-08 22:21
