Today I Learned: Why Your Brain Can't Tune Out Coworkers Even if You Want to

While the pandemic upended our lives, it taught us one thing about work: there are entire industries that can function outside the office (e.g., the creatives). But because of management’s obsession with control (see Jeremy Bentham's 18th-century concept of the "panopticon"), return-to-office mandates were implemented post-pandemic. Worse, offices were reconfigured into open-plan layouts that are sold to us as "avenues for collaboration." The next thing you know, it’s 4 p.m., and you haven't finished a single task—or even meaningfully collaborated—yet you’re already exhausted. If you were in the quiet of your home, you would have already crossed off four items on your to-do list, eaten lunch in peace, and maybe even squeezed in an evening workout. So, why are we at our worst in an open-plan office? Answer: The Irrelevant Speech Effect (ISE).

Also called Irrelevant Sound Effect, ISE in psychoacoustics refers to cognitive decline and increased acoustic distraction brought about by speech sounds, music, and other background sounds. Studies about this have been published for decades, and it has been consistently concluded that irrelevant sounds inhibit one's serial recall and/or short-term memory, specifically.

Several studies have also been conducted on the effect of irrelevant sound in open-plan offices, where—obviously—noise is the main source of distraction and discomfort among employees. And while you can try to tune out the noise, it's not as easy as it sounds. The brain constantly processes sounds from the environment, so in a noisy setting, it works really hard to filter out irrelevant noises. This is why you feel tired even though, technically, you haven't even done anything. Your brain literally fought a war against noise for eight hours.

In a laboratory experiment published in 2025 in Applied Acoustics, researchers from France focused on noise intelligibility (or how clearly speech can be understood amidst background noise) in open-plan offices. Just imagine the noise in this set-up, you have a one-sided snippet of an exchange, muffled discussions coming from the next table, laughter and intense reactions without context (as you're not part of the conversation to begin with), and all other kinds of office noise.

Empirical results reinforced what we already know: noise affects cognitive task performance. "The novelty is that the results show that not only simple cognitive tasks using short-term memory are impacted by this phenomenon, but also activities requiring deeper processing, such as finding and summarizing information in a set of written documents," its conclusion said.

A 2015 study, published in the Journal of Environmental Psychology, likewise explored the effects of irrelevant speech rate (as well as temperature and ventilation) on performance and satisfaction in open-plan offices. The publication by Finland-based researchers from Finland supported the view that special care should be paid to the holistic design of the indoor environment in open-plan offices. Their study provided strong evidence that the combination of high intelligibility of irrelevant speech, high room temperature, and low ventilation rate impairs the perceived working conditions and cognitive performance.

The effect of irrelevant speech on physiological stress, cognitive performance, and subjective experience, particularly heart rate variability, was the main topic for a 2024 study published in the International Journal of Psychophysiology. It concluded that: "Irrelevant speech presented at a moderate level (50 dB LAeq) impaired performance, worsened experience, and increased physiological stress compared to the quiet condition without speech (35 dB LAeq)."

It further suggested: "...working during [irrelevant] speech is clearly stressful, reduces performance, and causes annoyance, workload, and a less pleasant sound environment, which cannot be corrected by practice or habituation. Therefore, the exposure to irrelevant speech should be minimized in workplaces where people must perform cognitively demanding tasks."

Why not just wear noise-canceling headphones? While this could work for some and drown out the noise with music on full volume, there are others who can also be distracted by the music directly in their ears. I, for one, listen strictly to either string quartet playlists on Spotify or a mix of nature sounds via A Soft Murmur (often jokingly called by colleagues as "kuliglig sound"). Otherwise, I would be typing the lyrics I'm hearing in this article I'm writing—wouldn't it be nice if we were older, then we wouldn't have to wait so long, and wouldn't it be nice to live together in the kind of world where we belong....

A 1999 study published on Applied Cognitive Psychology compared the level of distraction of background music on the cognitive test performance of introverts and extraverts. Results showed that playing music had a detrimental effect on immediate recall in the memory test for both groups. Introverts also performed significantly less while completing a reading comprehension task with the music on. For others, having the music on is an extra process for the brain (on top of waging a war against noise).

As long as we're discussing the use of headphones, it's also interesting that a 2018 Harvard Business School study found that "rather than prompting increasingly vibrant face-to-face collaboration, open architecture appeared to trigger a natural human response to socially withdraw from officemates and interact instead over email and IM." Empirical data showed that the volume of face-to-face interaction decreased by 70 percent, compared to electronic interaction.

Work, especially ones that need your 100 percent, requires physical and mental boundaries. And in an effort to be productive, people try to self-isolate at their stations. Couldn't really blame those who'd rather put on earphones (if only to pretend listening to music) to ward off co-workers who tap you on the shoulder to ask one question after another.

It doesn't help that we're just wired to listen in on snippets of chit-chats we shouldn't care about, or it could also be that we just love gossiping—although that could be a factor. A 2010 study published in Psychological Science found that overhearing just one side of a conversation is much more distracting than hearing both sides. Maybe you don't even intend to listen, but your brain wants you to. Lauren Emberson, currently a postdoctoral associate in psychology at the University of British Columbia, said that this is because we're wired to ignore predictable things and pay more attention to unpredictable ones. "Halfalogues," as she calls them, are unpredictable, while listening in to an audible conversation is much more predictable. This is also why we unintentionally listen to other people's phone calls on the bus.

A 2021 article published on the World Economic Forum suggests a significant relationship between open-plan office noise and physiological stress. Results show an increased negative mood by 25 percent, and this comes from testing participants in a simulated open-plan office for just eight minutes at a time. You can just imagine the stress level after spending four to eight hours in a similar set-up. (Or, you don't even have to imagine, you already know what we're talking about.)

This study, however, posed a limitation: "While there was no immediate effect on reduced work performance, it is reasonable to assume such hidden stress over the longer term is detrimental to well-being and productivity."

So if return-to-office, especially in an open-office layout, is detrimental to productivity, mental and physical health, and overall well-being, why do we even go?

References:

Bernstein, Ethan S., and Stephen Turban. “The impact of the ‘Open’ Workspace on Human Collaboration.” Philosophical Transactions of the Royal Society B: Biological Sciences, vol. 373, no. 1753, 2 July 2018, p. 20170239, https://doi.org/10.1098/rstb.2017.0239.

Emberson, Lauren L., et al. “Overheard cell-phone conversations.” Psychological Science, vol. 21, no. 10, 3 Sept. 2010, pp. 1383–1388, https://doi.org/10.1177/0956797610382126.

Jahncke, Helena, et al. “Cognitive performance during irrelevant speech: Effects of speech intelligibility and office-task characteristics.” Applied Acoustics, vol. 74, no. 3, 24 Oct. 2012, pp. 307–316, https://doi.org/10.1016/j.apacoust.2012.08.007.

Lang, Susan S., and 2010 May 24. “Overhearing Cell Phone Chats Reduces Cognitive Performance, Study Finds.” Cornell Chronicle, Cornell University, 24 May 2010, news.cornell.edu/stories/2010/05/half-heard-phone-conversations-reduce-performance.

Poncetti, Nicolas F., et al. “Effect of hearing impairment on fatigue and annoyance caused by task-irrelevant speech: A working day simulation in an open-plan office.” Applied Acoustics, vol. 243, 5 Nov. 2026, p. 111149, https://doi.org/10.1016/j.apacoust.2025.111149.

Radun, Jenni, et al. “The effects of irrelevant speech on physiological stress, cognitive performance, and subjective experience – focus on heart rate variability.” International Journal of Psychophysiology, vol. 200, 18 Apr. 2024, p. 112352, https://doi.org/10.1016/j.ijpsycho.2024.112352.

Sander, Libby. “The Surprising Toll Open-Plan Offices Have on Our Mental Health.” World Economic Forum, 6 July 2021, www.weforum.org/stories/2021/07/open-plan-office-noise-stress-mental-health-mood-work-employment-employees-welfare/.

Varjo, Johanna, et al. “Simultaneous effects of irrelevant speech, temperature, and ventilation rate on performance and satisfaction in open-plan offices.” Journal of Environmental Psychology, vol. 44, 28 Aug. 2015, pp. 16–33, https://doi.org/10.1016/j.jenvp.2015.08.001.

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