Join the call, and the rest of your Mac steps back.

The sequence is always the same. Music is playing, a Slack channel is chiming, a YouTube tab is running in the background — and then the Zoom window opens and you have about four seconds to find the volume key before the whole call hears your playlist. Pressing that key turns everything down, Zoom included, so now you can't hear the person talking either.

macOS has no per-app volume, and no built-in rule that says "when a call starts, lower the other things." Below are the three routes that genuinely work on a Mac in 2026, in order of how little you have to do.

First: decide whether you want mute or ducking

These are different, and the difference matters more than the tool you pick.

• Mute is binary. Background audio goes to silence and stays there until something turns it back on. If that something is you, you will forget, and you will spend twenty minutes after the call wondering why Spotify looks like it's playing but you can't hear it.
• Ducking drops background audio by a fixed amount — MixPill uses 20% of its previous level — and puts it back when the call ends. The call is unambiguously the loudest thing on your Mac, but you still hear the album finish, and you still hear the doorbell in the podcast you were half-listening to.

Ducking is what broadcast has done for decades when a voice comes in over a music bed, and it is almost always what people mean when they say "mute everything for calls." Set it up as ducking and you never have to undo it.

Route 1 — automatic, triggered by the microphone

The most reliable trigger for "a call has started" is not "Zoom launched" — Zoom is often already open — and it is not "a meeting is in my calendar," because half of them get cancelled. It is something on this Mac just took hold of an audio input. That happens the instant you join a call, in every conferencing app that exists, including ones running in a browser tab.

MixPill's Auto-Ducking works from exactly that signal. It does not keep a list of conferencing apps to watch for, so Zoom, FaceTime, Microsoft Teams, Google Meet in Chrome, Discord, Slack huddles and whatever ships next year all work without anyone adding support for them. The moment any process takes an input, every other channel drops to 20%. When that process lets go — you leave the call, you quit the app — they climb back on their own.

Worth being precise about the permission, because "watches the microphone" sounds alarming: MixPill asks Core Audio which processes hold an audio input. It does not open the microphone and it never requests microphone access. The one permission it does need is System Audio Recording, which is what macOS requires for the Core Audio process taps the whole app is built on. There is a full breakdown of every permission if you want to read it before installing anything.

The honest trade-off: because the trigger is "any input", a dictation tool or a voice memo will duck your music too. If your workflow involves talking to your Mac all day for reasons unrelated to meetings, route 2 will suit you better.

Auto-Ducking is part of MixPill Pro. Per-app volume and mute are free — see what's in each tier.

Route 2 — a Shortcut on a trigger you choose

If you want the trigger to be something specific rather than microphone activity, macOS's own Shortcuts app can drive the mixer directly. MixPill exposes App Intents for setting a volume, muting an app, applying a preset and toggling ducking, which means Shortcuts and Focus filters can run them.

A setup that works well:

1. Create a Focus called Meetings in System Settings → Focus.
2. In Shortcuts, build a shortcut that applies your Call preset — a saved set of levels with music and browser pulled down and the conferencing app left alone.
3. Add a Focus filter, or an automation on the Focus turning on, that runs it.
4. Build the mirror shortcut for Focus turning off, restoring your normal preset.

This is five minutes of one-time setup and gives you a trigger that is exactly the one you want: a calendar event, a time of day, a Focus you turn on by hand. Since macOS can turn a Focus on from a calendar event, you can get "my 10:00 stand-up ducks everything at 09:58" without any mixer watching anything.

The longer guide on ducking covers how the two routes compare in more detail. They are not mutually exclusive — automatic ducking as the default with a Shortcut for edge cases is a perfectly reasonable setup.

Route 3 — free and manual

If you don't want an automation at all, per-app faders plus a keyboard shortcut covers most of it, and costs nothing. MixPill's per-app volume, mute, solo and metering are free for unlimited apps with no trial and no nag. Open the menu bar item, drop Spotify and the browser, leave the call app where it is. With global hotkeys turned on it is one keystroke — that is the only thing that needs the Accessibility permission, and skipping it leaves everything else working.

The reason this is worth mentioning at all: it is instant, it is predictable, and there is no trigger to misfire. Plenty of people prefer it.

What macOS already does for free (and what it doesn't)

Before adding anything, take the free wins — they solve a real part of the problem:

• Focus / Do Not Disturb stops notification banners and their sounds during a call. Set it to turn on automatically when you share your screen. This handles Slack chimes but does nothing to music that is already playing.
• System Settings → Sound → Alert volume is a separate slider from your main output. Pulling it down permanently makes every system alert quieter without touching anything else. Most people have never moved it.
• Zoom's own output slider (Settings → Audio) sets the call level independently of your system volume, so you can raise the call rather than lowering everything else.

What macOS will not do, in any version shipping today, is lower one running app while another gets louder. That is the specific gap, and it is why this category of app exists at all — the background on why Core Audio works this way is worth ten minutes if you're curious.

One thing none of this fixes

Everything above is about what you hear. None of it changes what the call hears from your microphone. If your problem is the other direction — your keyboard, your fan, the street outside going down the line — that is a separate set of controls, and most of them are free and already on your Mac. We wrote that one up separately: how to stop keyboard noise on Mac video calls without a subscription app.

Common questions