Using a monitor with a mic included? Many modern monitors have mics, and it’s possible your app or computer are defaulting to that mic rather than your Mac’s internal microphone. If you recently downloaded an app that requires permission to use your mic, it could be causing issues that prevent the mic from working at all. A Mac or MacBook microphone not working can be caused by apps. This is a good time to return or repair your Mac. Though all Macs go through quality checks, sometimes things are just broken. If you recently purchased your Mac, it’s possible the mic is just broken. There could be several reasons for a Mac or MacBook mic not working. Reasons why Mac’s Microphone stopped working