The Psycho-Acoustics of Work


An event which presented the relationship between sound characteristics in the office and the human sensations they provoke.

Presented by Dr. Nigel Oseland, Workplace Strategist and Environmental Psychologist and chaired by Mark Eltringham, publisher of IN Magazine and This was a live presentation that took place July 2021.

Dr. Nigel Oseland PhD CPsychol
'I started life as a researcher in the Building Research Establishment, looking at how we can make homes and offices more comfortable, and how we can make offices more productive. After 11 years of research, I realised I needed to disseminate this information and talk about the practical aspects of it, not something that comes naturally to researchers and academics. Over the last twenty years, I have focused on communicating my learnings. I specialised in environmental psychology, which is about how human behaviour is impacted by the built environment. My PhD was actually in thermal comfort but today it's all about acoustics.'

'So, what is psychoacoustics? Psychoacoustics is about how our physiology and psychology are affected by sound; how we respond to it and how we behave. Or simply, how people perceive, interpret and react to sound. Psychoacoustics is a strand of psychophysics, such as how people perceive, interpret and react to temperature, or to air quality. That's how we phrase psychoacoustics, but when you talk to acousticians and how we measure the impact of noise on people, they very quickly get into a whole debate about how you measure sound. They have lots of different measurements that they use: sound pressure levels, the most obvious one but you've also come across reverberation time species, speech transmission index.' 

'If you go to an acoustic conference there's lots of debate about how we measure sound. The problem is they're missing the point because when it comes to noise, if you look at the literature, sound level itself only accounts for about 25% of the variation in noise annoyance. So, there's another 75% of something else that affects noise and I want to focus on the 75%, because I think there's more to be learned there.'

'Noise is an unwanted sound and because it's an ‘unwanted’ sound, we - people -  decide whether a sound is a noise or not. It's what goes on in our heads. Is a dripping tap a noise? A dripping tap has quite a low sound level and if there's a dripping tap, over there in the corner right now, we probably wouldn't even notice it. But at night, that little dripping tap sound with a few DB, suddenly becomes really annoying. It becomes a loud noise. So it's not just about sound levels and other factors, noise is down to us and how we receive it -  it's a psychophysical variable. If you look at the literature around psychoacoustics, there are many different factors that affect how we perceive/interpret noise.' 

'Today I'm going to talk a bit about personalities, but also other factors. Control - whether people believe they have control over noise or not is key. Activity - what work activities you do and where you do it. Social demographic variables like age, plus your ability to screen out noise, and then factoring in the different personality types. We sometimes talk about sensory seekers and sensory avoiders, and people who are hypersensitive and hyposensitive. For example, you can be sensitive to noise but not necessarily be sensitive to light or temperature. Some people are highly sensitive to noise, while other people are really good at screening noise out.'

'We created an online survey with over 2000 respondents. We asked questions about noise, such as do you find the noise in the workplace satisfactory, does it affect your work performance, does it affect your wellbeing, your stress etc. We asked workplace questions such as where you sit, what kind of space you are in, and we asked about socio-demographics, such as how old you are and so on. What was unique about our survey was that we investigated personality and asked the respondents to actually fill out a personality profile.'

'The first thing we learnt is that two-thirds of the people said that noise had a negative impact on their work. If we're creating environments where two-thirds of people say that they can't work because of noise, and only 10% of them saw this as a positive effect, then that’s a huge problem! It's not just our surveys that have these results,  the Leesman Index also found similar results. The big three killer variables are noise, temperature, and indoor air quality. These basic hygiene factors are what is affecting us negatively.'

'So, what do we do to overcome these? What are our coping mechanisms? Note that this survey took place pre-Covid. At that time, 45% of people wore headphones, and actually, these days that number has increased. That's great - you can listen to music and you can filter out noise disruptions. But particularly these days, if we are coming into the office, we're coming in specifically to interact, collaborate and teamwork. If people are wearing headphones, it misses the point of being present in the office. The other issue we found is that people come in early, or stay late, to complete the work in a quiet environment. Pre COVID 40% of our sample said they would make a conscious decision to work from home to avoid the noise distraction. Their solution was to go home! One finding I think is particularly interesting is that what we tend not to do is talk to our colleagues to work out a solution for the noise disruption. 
So back to personality. We measured five personality traits. I'm only going to talk about two today, and it's the two that Eysenck introduced: namely extraversion/ introversion and neuroticism versus emotional stability. By and large personality types divide into these two main groupings.'

'Extroverts are social, outgoing. They enjoy the company of others over being on their own. They tend to be outspoken and say things without thinking it through. Whereas introverts tend to be more thoughtful; they think things through, they look things over. When they say something it's normally something well-considered, and they are quite happy with their own company and not the company of others. Some people say extroverts get energised by other people whereas introverts find other people drain their energy. Neither is good nor bad, and there is roughly 50% of each in any society. 
Neuroticism is associated with nervousness, apprehension, anxiety. People who are more neurotic tend to dwell on things and think about the past and they are apprehensive about the future. Whereas emotionally stable people are just a little bit more calm and relaxed. Emotionally stable introverts are often the backbone of any organisation. There are views by people, such as Susan Cain, that we are designing offices for extroverts and so offices tend to be stimulating, buzzy, noisy and colourful. But that doesn't suit the introvert. We're all different and we should embrace that difference in workplace design. 
We used different scales of noise to understand how it affects your productivity, your stress, your wellbeing, your performance, and your overall ability to work. Following our research, whilst the difference in ratings were not large, they were statistically significant and robust enough to suggest that there are differences between how the emotionally stable tolerate noise in the workplace versus the neurotic. It is apparent that emotionally stable people can tolerate noise in their office better than the more neurotic. In addition, the more neurotic people are less favourable about the unpredictability of hot desking. 

'If we look at the other scale of the extrovert/introvert personality then the differences were a little bit more significant. What this says in terms of performance, is that extroverts cope with noise better than introverts.'

'And when you take out private office users and you focus only on the open-plan environment, you see that the extroverts can tolerate noise better than the introverts. The open-plan office has a more negative effect on introverts. In terms of where people are sitting, we broke it down into open-plan users with people who've got an assigned desk versus those with unassigned desks (that are hot desking). We then looked at those in private offices, and more mobile remote workers (obviously this was pre COVID so a smaller group than now). When you read a lot of acoustic literature, it states that to solve acoustic issues, everyone needs their own office. What our data shows is that it's not necessarily the best solution; it can cause other issues.'

'Remote workers tend to cope with noise better than people with open-plan allocated desks, and the people in private offices are no better off than those in open-plan. In addition, people using hot desks often fare better. Our understanding is they can choose where and when they work so they've got more control over the noise: if they're in a noisy space they could move to a quieter space, and so on. Having control is a huge coping mechanism for noise. With the remote workers, they can work from home occasionally so can control the noise that way. It's not about open-plan versus private offices, that's not the argument or the solution. It's about understanding the personalities - and let's face it, you're in the design industry: how many private offices are you putting into buildings at the moment, not many! Open plan is here to stay – so our job is to make it work.'

'Noise impacts and has a more negative effect on introverts particularly those who have allocated desks in open plan compared to hot desks. Introverts seem to be able to cope with noise better when they have remote working options, that is when they have more control. Open-plan assigned desks are the worst-case scenario for introverts but it has less impact on extroverts. You can also see that when people are doing focused analytical work tapping into deep knowledge, what they really struggle with is assigned desks and open-plan, Whereas remote workers seem to be able to cope with it. 
So, if you put all that together, the “perfect storm” is analysts/introverts in an open-plan office with assigned desks. That's where you get a problem, but that's just quite a small percentage of people in an organisation. Now, if you're a research organisation, and that's the majority of your people, then you need to cater for that in some way. But the answer isn't just giving people private offices.'

'So right at the start, I said that sound level only accounted for about 25% of our perception of noise. We looked at all these different variables and they accounted for 57% of psychological  - or psychophysical variables. But we’re starting to get a better understanding of how we can predict noise in offices, and it's not just about sound levels but about other factors. The ability to screen off noise is a key one, plus the coping mechanisms where people have a perceived choice that they can affect the noise control. It's interesting that it is perceived control rather than actual control, where people think they have options and are able to move etc.. So, we're getting closer to understanding the noise issue and it's not just about sound levels.'

'We converted all our research findings into a bit of guidance, summed up as DARE. If you can, in your designs look at how you can ‘"DISPLACE” noisy activities. Provide areas where noise can always take place; such as meeting pods, meeting rooms, cubicles, high back seating where people can have a chat etc. These areas need to be away from the main desking areas, providing spaces where people can go so they are not distracting others. Even introverts, who are doing detailed analysis, need to interact and socialise with their colleagues. You need to provide spaces that allow for this activity otherwise people will do it in the main workspace. If there's five of you in a team sitting around the table and two of you are having a chat, it's not a problem because you want that tacit knowledge and you will be doing similar projects and you're learning from each other. But if someone not part of the team was also sitting amongst them then, they would find it disruptive.
Give people the option to “AVOID” noise. This can be done through a choice of work settings. Going to different spaces in the office, occasional home-working and empowering people to get up from their desks, as well as empowering them to tell their colleagues to move to a place to have a meeting etc. “REDUCE” is all about noise absorption; good absorption on the ceiling, good absorption on the walls and using carpets for absorption. Absorption is an acoustician’s friend, the more absorption you can put into the space, the better. If you are going to have an exposed ceiling, put in acoustic rafts and baffles for example, which helps mitigate noise transference across the workspace. “EDUCATE” is about behaviour. We quite often talk about noise, but we're actually talking about distraction, and that distraction is normally caused by other people. Shouting out over the workspace, walking around the office on a mobile phone or tapping colleagues on the shoulder and asking for their help when they are in the middle of something. A lot of this is just behavioural and poor office etiquette. 

'In the guidance document, we have a set of assessment procedures, which is mostly survey work, where we start to look at personality roles and activities. We believe the solution needs to be layered. The layering begins with the basic sound treatment including absorption - the realm of the acoustician. It then moves to activities and roles, and then creating activity-based zones where people can work on their different activities. 
And then we come on to our next layer of sophistication, which is where we start saying what are the different personalities, how are the teams made up, is that a team of introverts or a team of extroverts. Let's start to think about how we can sort those people out. I still find it amazing that organisations run personality tests to see where a person fits in the organisation, to find what job suits them best, and then they are seated amongst everyone else, and you can have a really loud extrovert next to a quiet introvert and so on. 
The final layer is all about education and etiquette. I always recommend an office charter - guidelines on how we can all behave in the open plan. It sounds trivial, but some personality types - highly conscientious people - need house rules to refer to. This allows colleagues to have open conversations with each other regarding noise disruption.'

'We asked an architect to design a space for us with an exposed ceiling, hard floors, low screens - all very clean and clinical, showing people doing different activities. We then looked at what can be introduced to mitigate noise.'

'We introduced ceiling acoustics, wall panel acoustics, and aspects that start to create different sounds for the different activities. There are biophilic elements; moss walls are great for absorbing noise, as are bookshelves with books. Barker's behavioural settings state that we know how to behave instinctively in a library or a church and people then speak in lower voice tones, so  books are a visual clue and also are great for absorption and creating zones. Plus meeting pods can be added, and desk screens can be a little higher and covered with absorption materials to mitigate noise.'

'Obviously, we can't design for every individual, but you can understand the makeup of the different teams. Typically, certain personality types are attracted to certain jobs. So, analysts, researchers and finance teams tend to be more introverted, whereas sales and marketing people tend to be more extroverted. This is where you can start to understand the makeup of the personalities of the different teams. If they were highly conscientious, highly introverted, I would start by creating a calming team zone but also including an additional area for them to interact and socialise. Whereas if it's more of a marketing or sales team, you might want to start with a stimulating area, but give them spaces where they can retreat to a quiet place.'

'So, office noise is distracting and we can’t get away from that and open-plan doesn't help the situation. But it's a psychoacoustic issue, it's not just about the physical properties but what goes on in our heads, and whether we decide something's distracting and noisy, and whether we can filter it out or be disturbed by it. It’s about personality, activity, screening, where we sit, what we're doing - all those things affect the perception of noise.  Think about Displacement, Avoid, Reduce and Educate and also approach noise distraction by layering the solution.'

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Dr Nigel Oseland PhD CPsychol

Mark Eltringham

This event was co-hosted with Milliken Carpets, Insight Magazine and Connection Furniture.