MacBook Microphone Not Working — Fix Guide

What Does This Error Mean?

MacBook microphone not working is usually caused by an app not having microphone permission in System Settings, the wrong input device selected in Sound settings, or a connected headset being used as the input instead of the built-in mic. Check System Settings → Privacy & Security → Microphone first.

Affected Models

MacBook Air (all models)
MacBook Pro (all models)
MacBook (2015–2019)

Common Causes

App does not have microphone permission in macOS Privacy settings
External headset, USB audio device, or AirPods set as the input — built-in mic not selected
Microphone input level set to zero in Sound settings
Siri or Dictation microphone blocked by a macOS update requiring re-authorisation
Physical microphone grille blocked by a case or debris

How to Fix It

Check microphone permission for the app.

Go to System Settings → Privacy & Security → Microphone. Find the app that cannot use the microphone and ensure its toggle is on (green). If the app is not listed, run it and trigger a microphone prompt — macOS will ask for permission the first time.
Select the correct input device in Sound settings.

Go to System Settings → Sound → Input. Select 'MacBook Microphone' or 'Built-in Microphone'. If a USB audio interface, headset, or AirPods are connected, they may have taken over as the default input. Speak and watch the input level bar to confirm the mic is active.
Check the input volume level.

In System Settings → Sound → Input, check the Input volume slider. If it is at zero, drag it to 75%. Also check that 'Use ambient noise reduction' is not interfering with low-volume input.
Disconnect all external audio devices.

Unplug headphones, USB audio devices, and disconnect Bluetooth headsets. Then retest the built-in microphone. This confirms whether the issue is with the built-in mic or with the input routing to an external device.
Reset Core Audio.

Open Terminal and type: sudo killall coreaudiod — then press Enter and enter your password. This restarts the macOS audio system without rebooting. Core Audio can get into a bad state after an update or sleep cycle, causing the microphone to stop responding.

When to Call a Professional

If the built-in microphone does not appear at all in System Settings → Sound → Input with no external audio devices connected, the microphone hardware may have failed. Contact Apple Support.

Frequently Asked Questions

Why does my MacBook microphone sound muffled on calls?

The most common cause is a case covering the microphone grilles (located on the sides of the keyboard). Remove the MacBook from its case and test again. Screen cleaning cloths left between the lid and keyboard can also muffle the microphone.

Does resetting NVRAM fix MacBook microphone issues?

Sometimes — NVRAM stores audio hardware settings. On Intel MacBooks, reset NVRAM by restarting and holding Command + Option + P + R for 20 seconds. On M-series MacBooks, NVRAM is reset automatically during certain system updates.