How to Use Slack Notification Sounds to Improve Team Trust in Remote Work
Last quarter I stopped trying to fix our Slack habits with written agreements and started fixing them with sound. This is what happened on a six-person platform team spread across four time zones, from the start of January to the end of March.
The problem was not response time
Our on-call rotation worked. Pages got picked up. The thing underneath it did not.
We had a channel, #platform-help, where product engineers asked us questions. Median first reply sat around forty minutes, which looked acceptable on a dashboard. But three of the six had the channel muted, because during a deploy window it produces sixty-odd messages an hour, almost all of them bot output. So that forty-minute median was really two people carrying the channel and four people who had quietly opted out and felt a bit bad about it.
Requests then started arriving as DMs. A DM to one engineer is invisible to the other five, so the same question got answered three times in three private threads, twice with slightly different answers. Product engineers learned that the reliable way to reach us was to guess who was awake and message them directly. That is the opposite of what a shared channel is for.
Muting is a trust decision. People opt out of a channel when they cannot predict what it will cost them to leave it on.
The written agreement that did nothing
Our first fix was a norms doc. Use threads. Only @here for outages. Ask in the channel before you DM. We reviewed it in a retro, everyone nodded, and behaviour changed for about nine days.
It failed because it asked people to be disciplined about sending, and the pain was on the receiving end. Nobody unmuted #platform-help because the doc did not change what unmuting sounded like. It still sounded like sixty deploy bots.
What we changed in week three
I installed Chirpy, a macOS menu bar app that plays custom sounds for notifications. Worth being precise about what it is, because two people on the team assumed it needed workspace admin approval: it does not connect to the Slack API. There is no account to link and nothing to authorize inside Slack. It reads macOS notifications through the Accessibility API, entirely on the machine, and decides what to play from rules you write yourself.
Setup took about ten minutes per person. Install the app, grant it the Accessibility permission in System Settings, set Slack's own notification sound to None so you do not get two sounds stacked on top of each other, then write rules.
I wrote four and asked everyone to copy them as a starting point:
- Direct message from anyone. A short two-note chime, full volume. The point was to make DMs feel distinct so that when they stopped arriving, we would notice.
#platform-help containing our team handle, or the words "blocked" or "down". The same chime at about 70 percent volume. Close enough to a DM to register, quiet enough to tell apart.- Everything else in
#platform-help. A soft click at 20 percent. Audible if you are paying attention, invisible if you are not.
#prod-*, matched with a wildcard so it covers #prod-alerts and #prod-deploys. A low sustained tone for whoever was on call that week. Everyone else set that rule to silent and turned it back on when the rotation came round.
Rule priority mattered more than I expected. The catch-all in rule three has to sit below rule two, or every keyword match gets swallowed by the quiet click.
What broke
Three things, roughly in order of annoyance.
The keyword rule fired on ordinary sentences. "My coffee machine is down" got the urgent chime. We fixed it by requiring the keyword AND the channel, rather than the keyword anywhere, which cut the false positives to almost nothing.
One engineer set every rule to full volume on day one, hated the result, and nearly abandoned the whole thing. Per-rule volume is the feature that makes this work, and it is easy to skip past on the first pass. I should have said that out loud in the setup message.
The 20 percent click was inaudible on laptop speakers in a room with any background noise. That person runs it at 45 percent now. Sounds are configured per machine, not per team, so people diverged within a fortnight. I thought that would be a problem and it was not. What needed to be shared was which categories exist, not which sound each person hears.
Where we landed
By the middle of March all six had #platform-help unmuted. I did not run a stopwatch on reply times, so I will not pretend the median moved. What I can say is that the private DM traffic dropped off, questions got answered once in public where the next person could find them, and nobody has asked me to re-review the norms doc.
The useful part was not the sounds themselves. It was that assigning a sound forces you to decide, out loud, which messages deserve to interrupt someone. We had never done that. The doc assumed we all already agreed.
Chirpy costs $19.99 once, no subscription, and there is a three-day trial that does not ask for a card. If your team has a channel that half the people have quietly muted, start with that one. Take a look at Chirpy.