Change the sound input settings on Mac
If your Mac has separate ports for input and output, the sound input port has a microphone icon. If your Mac has only one sound port, it has a headphones icon () and can be used for both input and output.
You can use your computer’s internal microphone, your display’s microphone (if it has one), or an external microphone you plugged into your computer’s sound port.
On your Mac, choose Apple menu > System Preferences, click Sound, then click Input.
Select the device you want to use in the list of sound input devices.
All sound input devices available to your Mac are listed. If your display has an internal microphone, it’s listed as “Display Audio.”
Do any of the following to adjust your sound input settings:
Adjust the input volume: Drag the volume slider.
If you’re recording sound through your computer’s sound port, you can adjust the input volume to compensate for the sound source being too loud or quiet.
For example, if you’re recording loud music, lower the input volume so the recorded sound isn’t too loud or distorted. Or if you are recording someone who is speaking softly, increase the input volume so your Mac can better capture the person’s voice.
Capture less background noise when using your computer’s built-in microphone: Select “Use ambient noise reduction.” This option is not available if a 4-channel built-in microphone format is selected in Audio MIDI Setup.
Note: You can’t adjust the input volume for a digital input device using your computer’s controls. You must adjust the input volume from its source, such as a receiver.