Muting Sounds with SoundSource

The speaker icons shown next to volume sliders in SoundSource include sound waves that indicate the current volume level. In addition, those speakers also serve as handy dedicated Mute buttons.

Muted applications displaying red indicators

This makes it possible to mute sound from both your Mac’s default output device, as well as alert sounds and sound effects, or from individual apps. Favorite apps and other apps that have played sound in the past 15 second span are shown automatically in the Applications list, with a volume control.

Clicking the Mute button for your Mac's Input device will prevent any audio from being heard from that device. SoundSource thus provides a very useful Mute button for microphones and other inputs

For fast muting, use a global hotkey to display SoundSource, then use the arrow keys on your keyboard to select a device or application and mute it by pressing the Shift + Command + Down Arrow keys.