The Silent Caller
A highly disruptive issue for Mac users occurs during video conferences or audio recordings: the microphone volume seemingly has a mind of its own. You might be speaking clearly into your headset, but your colleagues suddenly complain that your voice has dropped to a whisper, or muted entirely. This happens because macOS, or specific communication applications like Zoom and Webex, actively monitor your audio input. If they detect loud background noise, or if they think you are speaking too loudly, they will automatically slide your microphone input volume down to compensate, sometimes muting you completely by accident.
How to Disable Auto-Gain Control in macOS
macOS natively attempts to normalize your microphone volume. To ensure your mic stays exactly at the volume level you set, you must disable this ambient noise reduction.
1. Click the Apple logo () in the top-left corner of your screen.
2. Select System Settings (or System Preferences).
3. In the left-hand sidebar, click on Sound.
4. Look at the main pane and click on the Input tab.
5. Select your active microphone from the list of devices.
6. Look for a checkbox labelled Use ambient noise reduction.
7. Uncheck this box.
Now, set the “Input volume” slider manually to your preferred level. macOS will no longer attempt to dynamically adjust this slider while you are speaking.
How to Disable Auto-Adjust in Third-Party Apps
Even if you disable the macOS setting, communication apps often apply their own aggressive auto-gain control, which overrides the system settings.
If you use Zoom:
1. Open Zoom and click the gear icon to access Settings.
2. Click on the Audio tab.
3. Under the Microphone section, uncheck the box labelled “Automatically adjust microphone volume.”
If you use Microsoft Teams:
1. Open Teams, click the three dots next to your profile picture, and select Settings.
2. Click on Devices.
3. Look under the Microphone settings and turn off the toggle for “Automatically adjust mic sensitivity.”
By disabling these software-level corrections, your microphone will output a consistent, fixed audio signal based entirely on your physical hardware settings.