Is the sound of conversation the optimal noise level for office workers? Stewart Forsyth goes in search of that elusive sweet spot.
Office reluctance is an issue across the post-pandemic world. But there are great reasons to be in the office. Working alongside others creates opportunities. There’s the chance to collaborate and innovate. To share skills and knowledge. To pick up on the backstory to what is going on – that can be hard to intuit over a screen.
But still, office workers stay away.
In New Zealand, a comprehensive study by Rachel Morrison and Keith Macky of AUT found that the more open-plan the office was, the less pleasant it was for office workers.
Collaboration, engagement, and support from managers also dropped back.
There are all those possible benefits of working together, but they’re not being fulfilled in many open plans.
One reason people don’t like open-plan offices is the noise. Open-planners use earphones to block the buzz or they drown it out with music.
A wide-ranging and powerful study of American office workers led by Karthik Srinivasan (and 14 co-researchers) published this year in Nature measured the intensity of the noise these workers experienced and tracked their well-being in real-time.
It is intuitive that more noise is more distracting and it takes an emotional toll. A 2022 study also in Nature, found that listening to motorway noise increased depressive symptoms. Higher volume noise (above 95 decibels) can mean lower performance on mentally demanding tasks. A World Health Organisation report identified noise as second only to air pollution as a cause of health problems. The Srinivasan study found that louder noise reduced the well-being of office workers. So did quiet.
The sweet spot
There is a sweet spot. For the office worker that sweet spot is around 50 decibels – or about the noise level of a conversation at home.
The researchers measured the variability of these office workers’ heart rate. More heart rate variability is a good thing – it indicates the responsiveness of the nervous system to the dynamic of context. Responsiveness to noise, and especially the sensitivity to the 50-decibel sweet spot was more notable for two groups. Those with high blood pressure, who were perhaps more sensitised to stress, and those doing computer-intensive work.
Some offices broadcast white noise in their open plan area to screen out private conversations. Such background noise has been demonstrated to help those with an ADHD diagnosis keep on task.
There is also limited evidence (Mohamed Awada and colleagues, in Nature, 2022) that white noise helps neurotypicals as well. At 45 decibels, but not at 65 decibels, white noise resulted in better performance on cognitive and creativity tasks and no increase in stress.
Evolutionary influence
Is there something in our evolutionary experience that might make us more tuned in to sound at different volumes?
People like birdsong. A study across Europe found a strong relationship between the richness of bird life in 50km squares and the happiness of those living in those zones (this included 43,636 people in 34 European countries).
In the study of motorway noise already noted, listening to birdsong (at similar volumes to the motorway noise) reduced both anxiety and paranoia.
Birdsong is typically a little below the 50-decibel sweet spot at around 40 decibels (though try telling that to low-flying kaka or a young tui trying out its singing routine!).
Think of the last time you were in the bush, or a park, and it was very quiet. Was that a peaceful, easy feeling? Or disconcerting? Birds go quiet when ambush predators are lurking. Silence is a signal that danger could be lurking. Time for paranoia.
In contrast, visualise a small group of birds gathered together and chatting amicably. Being part of this would have signaled belonging and safety. Getting that vibe going in the office could help encourage people to get back to the workplace, even if only for a few days of the week.
Stewart Forsyth is a leadership coach and writes a Substack newsletter. For more go to: http://www.fxc.co.nz
