On a dreary day in the slog between Christmas and dorm sex video at christian schoolNew Year's last December, I was procrastinating at work. (If you try to tell me that you get any work done after Dec. 15, you're a dirty liar.)  

Deep into my procrastination efforts, I found myself in the Slack app's settings, where a little poking around bestowed me with the greatest gift of my holiday season: the Hummus Slack sound. 

For those unfamiliar with the glory that is the Hummus Slack sound, it's exactly what it…sounds like. Among the rather normal notification sound options in Slack — which include Ding, Boing, and of course, the iconic and increasingly grating Knock Brush — is Hummus, which features a breathy female voice simply uttering the word "hummus." It makes absolutely zero sense but also, all of the sense in the world. 

I switched my Slack notification sound from the default Knock Brush to Hummus on Dec. 30, 2021. It's been three months now, and strangely, I actually feel pretty dang cheerful when I get a Slack message these days. I know: No sane person should feel joy when receiving a Slack message, but the funny little voice that whispers "hummus" when my boss is asking me to complete a task usually makes me giggle on my best days, and lets me exasperatedly sigh (or scream, depends on the task) at a silly sound on my worst days. Overall, I feel less stressed at the prospect of opening up the Slack app, and my brain feels a bit lighter than the days of the Knock Brush. I don't think I'm ever going back. 

Let's rewind. Why is there a Hummus Slack sound?

A fantastic question, my friend. I had the same thought. Amongst the Dings and Boings and even the more whimsical Whoas (which are all sound effects), why drop in just one spoken English word? And why make that word HUMMUS? I mean, if we were choosing amongst questionable dips and spreads, might I suggest ranch, Nutella, or even ketchup?!

The answer, though, is actually pretty adorable. As reported by The National,a Slack user back in 2016 was just as curious as us, and tweeted the company to find out Hummus's origins. Slack replied, and explained that it was an homage to one of their beloved coworkers. 

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Whoever Anna is, I want her to know that her dulcet tones have somehow lulled my stress-addled cerebrum down to more of an occasionally-frazzled-but-usually-OK brain, at least at work. And I guess thanks to the folks at Slack for making the Hummus sound available to all us plebeians, since it seems it was originally meant for just the Slack HQ inner circle. 

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While Hummus comes from coworker appreciation, the rest of Slack's sound options actually come from a video game. "Slack’s notification sounds are largely derived from its predecessor, Glitch, a video game from Stewart Butterfield and others that morphed into today’s Slack. It was the sound that players heard when they received a message," said a Slack spokesperson to Mashable in an email.

Knock Brush, specifically, was very important to Butterfield, who apparently wanted to include the sound that your tongue makes when you separate it from the roof of your mouth, while his musician friend Danny Simmons added in the sound of "pulling your thumb through a toothbrush." These two effects together combined to make the sound that has haunted so many of our workplace fever dreams.

I'm thrilled with my little Hummus sound these days. But I also wonder why Knock Brush made me so stressed in the first place.

There are more than 10 million daily active Slack usersas of 2019. I obviously can't be the only one that was feeling like Knock Brush was creating undue anxiety in my work life.  

A quick Google search for "Slack knock brush stress" revealed plenty of people who really understood me. A Reddit user posted the very same problem to r/cscareerquestions, asking for advice on how to reduce the anxiety that Slack's default notification sound induced.

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A lot of the tips were genuinely helpful, with only a few classic (read: annoying) Reddit users harping on OP for daring to check their Slack so often in the first place. And as you can see in the OP's edits, they seem to have actually found the same solution that I did by changing their Slack notification sound — albeit we don't know if they, too, chose the illustrious Hummus. But why have we all let Slack's sounds affect us so deeply?

If you've ever taken an Intro to Psychology course, you might suspect that this is a classic case of Pavlov's dogs. For those unaware, Russian physiologist Ivan Pavlov famously conducted an experiment where he classically conditioned dogs to salivate at the sound of a bell. He did so by continuously exposing them to food immediately after hearing the sound. And in our mysterious case of the stressful Slack sound, the analogy seems to align perfectly: Knock Brush is to stress as bell is to hunger. 

But brains are curious little things, and I wanted to know why sound has the ability to affect us so much, and specifically, induce or reduce a stress response. I've got plenty of stress in my life, and if I can find the reason as to why Slack's sound can be so stressful, maybe I can curate my entire life's soundscape to never stress me out again. (A girl can dream!)  

In a 2020 studypublished in the journal Brain Sciences, electrical engineering and psychology researchers investigated how certain types of music could affect stress levels. After exposing their test subjects to stressful situations, they examined how rap music, forest ambiance, and ASMR sounds affected stress, ultimately finding that ASMR and ambiance sounds actually helped reduce stress levels. 

While this doesn't explain why Knock Brush stressed me out so much, it does point to why Hummus was so relaxing in comparison; hearing my new favorite person Anna whisper "hummus" with every Slack notification is kind of like listening to ASMR. I would know – I get ASMR TikTok lives fed to me every night, and they always feature someone whispering into their mics. And the airy aspiration on the "huh" part of hummus? The slight British accent and almost intimate volume? Yeah, this is basically ASMR for dummies. It's me, I'm the dummy. 

And as to why Knock Brush elicits a stress response in my brain, I found the answer most easily explained by the actual definition of the word "noise." As per the Hearing Health Foundation's favorite definition, noise is really just any undesired sound, and noise itself typically triggers a stress response in the amygdala. After more than a year with Knock Brush, I truly did not desire its company. Coupled with my unwitting classical conditioning, it's no surprise that Knock Brush on its own became my personal manifestation of hell. Honestly, thank goodness I found Hummus when I did.

If you, too, are experiencing stress via Knock Brush, might I suggest these quick fixes:

In case I haven't made it clear: I am a Hummus Slack sound stan. Obviously, I would like to inspire the world to convert their Slack notifications en masse to all softly say "hummus." Please consider making this move. 

But if Hummus really just isn't for you, try any of the other Slack sound options. If you're stressed by Knock Brush, you've probably Pavlov'd yourself, and switching up your Slack soundscape should help at least a little bit. I highly recommend the bouncy "Yoink," the happy little "Hi," and the truly delightful "Ta-da."

And if you want to know what other people are into, I actually have the official ranked list of most popular sounds straight from Slack itself (where Hummus is obviously being underused!):

1. Ding (mobile default)

2. Knock Brush (desktop default)

3. Ta-da

4. Whoa!

5. Boing

6. Plink

7. Wow

8. Here you go

9. Drop

10. Hi

11. Yoink

12. Hummus

If all else fails, maybe just turn off Slack sounds entirely. The thought of not having a sound and potentially missing an important message is personally eons more stressful to me, but to each their own. And remember: Try to set some healthy work-life boundaries, and stop checking Slack after hours. Better yet, turn those notifications off outside your work hours completely. It's life-changing! 

Once your stress levels have been managed, feel free to redirect all that new energy toward joining me in petitioning Slack to add more random word sounds. I have a coworker who would drastically enjoy work more if we could get "Timotitties" in there.