Often when running meetups you’ll have several lively conversations going at the same time. This is a great problem to have, but it can make it difficult to get everyone’s attention for announcements.

Try using “Contagious Humming” when you need to silence a crowd:

Move to a prominent place in the room and use body language that says you have something to say.
Start humming at a low and constant tone.
Recruit a few compatriots to join in.
- If the crowd has enough people familiar with the technique, generally about 20% of the room, looking expectantly at a few friends is often enough.
Wait for the hum to spread through the room. This can take a while, 30 seconds to a minute, just be patient.
- There will often be one or two holdouts, but they’ll usually finish their statement within about three to five seconds of noticing everyone else is humming. If not, call their name or have someone tap them on their shoulder to get their attention.
- Don’t try to start an announcement by talking over a holdout; in my experience that breaks the spell.
Let the hum fill the room for a few seconds after the last person stops talking. Then stop, take a breath, and thank the crowd. If you’ve done this right, they’ll see you preparing to speak and stop humming.
Say what you came to say.

Introducing this technique to a new group is often pretty easy. It helps to get buy-in from some deputies. Explain to a few social-looking people that you want them to call the room to order by getting everyone to hum, aside, then have them circulate through the room to pass the word while you and your starting conversational circle all hum. It’ll take a little longer but, in my experience, people catch on surprisingly quickly.

This can also be used to reset everyone’s volume. Meetups are often held in rooms with bare walls or floors, causing a subtle echo. Often people instinctually raise their voice to offset this, without even realizing they’re doing it, causing the other conversations in the room to get louder in response. This feedback loop can cause a cacophony that is deeply unpleasant for people with sensory issues, or who have hearing damage making it difficult to separate voices out from background noise.

This is a common technique, but it’s barely discussed online.^[1] I didn’t see it documented on LessWrong at all. I wanted this post to exist as a reference that I could link to.

Why does this work?

It’s not rocket science: when you’re humming, you can’t talk. This gradually spreads between conversation circles, as someone in each notices and either drops out of the conversation to hum or starts looking around in confusion to see why everyone has decided to be bees all of a sudden.^[2]

Humming is effective on holdouts because they notice that more than just their own conversational circle can now hear them. It is inherently awkward to suddenly be talking to a larger crowd who didn’t hear the first part of your point. Often people will try to finish their thought, go on for a few more seconds, and awkwardly trail off as they try to start a new sentence and get confused looks in response. Trust the process, this is fine, they’ll know better next time.

Humming is also calming, both to do and to hear. An article in Psychology Today tries to explain why.^[3]

Better Than Alternatives

The fact that you can’t talk while humming makes it better than other methods, like shouting over the crowd, or “clap X times if you can hear me”. Methods focused on sharp sounds like claps or yells can amp up a crowd, making them subtly more likely to keep talking and finishing their point.

Yelling or clapping also amps up you, the speaker. This is sometimes appropriate, if you’re leading a pep rally, or need the crowd to be energetic for some reasons. But this is best used sparingly, only when you actually intend the effect. Oftentimes you’ll want to calm, dismiss, or give logistical notes to a crowd. In those cases, humming for 30 seconds beforehand is better preparation for your own voice.

Give “Contagious Humming” a try and report back.

^{^}
This was one of the top search results, and it’s not even the focus of the post: https://experientialtools.com/2012/03/16/large-group-facilitation-tips/
^{^}
Their confusion can be very amusing, if you’re into that.
^{^}
Something about the vagus nerve?
https://www.psychologytoday.com/us/blog/the-compassionate-brain/202410/the-power-of-humming