How to mute your Mac's microphone quickly

You are on a call, the dog barks or a kettle starts, and you need to mute right now. The quickest way depends on what you are using. Here is what I could confirm for macOS, what the call app gives you, and how TapNoise can mute the microphone with a knock on the MacBook.

The built-in options

I could not find a system-wide keyboard shortcut in macOS that mutes the microphone. Searching turned up mostly third-party utilities and forum posts, and I could not confirm an Apple article that describes one. So treat the built-in options as limited.

Use the mute control in your call app. This is usually the most reliable option, because the app knows which microphone it is sending. Most meeting apps have a mute button and a keyboard shortcut for it. Find the shortcut in the app’s settings, and learn it before your next call.

Watch the menu bar indicator. When an app is using the microphone, macOS shows a small indicator in the menu bar, so you can tell whether anything is listening. It is a good check after you think you have muted. It is not a switch.

Muting with a knock in TapNoise

TapNoise has Knock commands. Knock on the MacBook near the trackpad, and it can mute your microphone. Knocks are picked up by the motion sensor, and the setting is off until you turn it on.

To set it up:

1. Open TapNoise Settings and go to MacBook.
2. In the Knock commands card, turn on Knock to control your Mac.
3. Check the two pickers. Knock twice defaults to Play / pause, or mute mic in calls.

That default is the useful one for a call. When a microphone is in use, a double knock mutes or unmutes it. When no app is using the microphone, the same knock plays or pauses music. You can also set Knock twice to Mute / unmute microphone if you want it to work all the time.

TapNoise mutes the default microphone itself. It uses the microphone’s mute switch where the device has one. Otherwise it turns the input volume down to zero, and when you unmute, it puts the level back where it was. Because it mutes the input, every app that uses the microphone goes quiet, not just one call. Tappy on the desktop shows when the mic is muted.

The three-knock option defaults to Lock the screen, which needs Accessibility permission. Leave it there if you do not need it.

Things to know before you rely on it

• Knocks need an Apple silicon MacBook. The Settings page says knocks need an Apple silicon MacBook from M1 Pro or M2 Air on. On other Macs the toggle is greyed out.
• Test it before a call. Knock a few times while nothing is happening, so you know how hard you need to knock and what it does.
• Typing never counts. TapNoise says so in the Settings copy, and it is the reason knocks are separate from key presses.
• Quiet during calls is a separate setting in General. It silences TapNoise’s own sounds during a call, which is what you want when you are muting.

Knock commands are part of the TapNoise license. A one-time purchase is US$7.99 plus tax, with a 14-day money-back guarantee.

The short version

For a call, use the mute button or shortcut in the app you are using. That is the most reliable option. If you want a physical way to mute the microphone from the MacBook itself, turn on Knock commands in TapNoise and use a double knock during the call. Test it first, so the first time you use it is not in front of your colleagues.