macOS has some impressive audio controls such as the built-in ability to output audio to multiple devices. If you were to attempt the same on a Windows system, you’d likely need to install a third-party app, and it wouldn’t be very reliable. That sad, macOS also falls short in some areas when it comes to audio. Case in point: you cannot mute an app on macOS out of the box.
Windows 10 has the volume mixer which lets users mute anything, even system sounds. On macOS, you need to install a free app called BackgroundMusic to do the job.
Mute an app on macOS
BackgroundMusic installs as a package and runs from the menu bar. It’s a fairly old app and its 64-bit so you’ll be able to use it on Catalina however, the latest version seems to be problematic. Try installing it and running the app. If it doesn’t work, look for version 2 (go through the release history on Github), and try installing that instead.
Once installed, click the app’s icon in the menu bar and reduce the volume for an app to zero. If you want to silence all system sounds, drag its volume slider to zero. The app will list apps that are currently running in its main menu and you can find other apps under More Apps.
If you need to mute an app that isn’t listed in the menu, make sure it’s running. If that doesn’t get the app to show up in BackgroundMusic’s menu, play something in the app.
BackgroundMusic needs to be running at all times in order to mute an app. This means that you need to add it as a start up item on macOS. More importantly, the app will run after system start up which means you cannot use it to silence the start up chime on macOS.
Apple has never been shy about ‘borrowing’ features. Night Shift is one very recent example of this so it’s a wonder that it hasn’t added a Windows 10-like volume mixer to macOS. Mac users often look for ways to get a volume mixer and usually end up finding BackgroundMusic as a viable, free way to get it.
There are other apps, besides BackgroundMusic that can mute an app on macOS but they cost more than it’s worth spending on something as small as this. BackgroundMusic has a few other features so look around and see if it addresses other sound-related needs you might have on macOS.
Source = “https://www.addictivetips.com/mac-os/mute-an-app-on-macos/”