iCanHazShortcut - Simple shortcut manager for OS X 10.8 or higher.
Mutify - Use a shortcut on any Mac device to mute your microphone
CustomShortcuts - Customize your Mac menu keyboard shortcuts for free.
MuteTab - Better tab muting in Chrome
Keysmith - Create custom keyboard shortcuts for your Mac and the web
Mute Intercom - Mute annoying sounds from Intercom 🔕