Change the sound input settings on Mac
Depending on your Mac model, there may be one or two sound ports. If your Mac has separate ports for sound input and output, the input port may use either a microphone icon 
or a sound input icon 
. If your Mac has only one sound port, it may have a headphones icon 
or no icon at all. This sound port supports stereo output and mono input (such as a headset with a built-in microphone).
You can use your computer’s internal microphone, your display’s microphone (if it has one), your iPhone microphone or an external microphone plugged into your computer’s sound port.
Note: The Recording Indicator 
in Control Centre shows you when your computer’s microphone is in use or when it was used recently. This indicator increases security and privacy on your Mac by letting you know if an app has access to the microphone. The indicator turns on when you access the Input pane in Sound Settings.
On your Mac, choose Apple menu
in the sidebar. (You may need to scroll down.)Click Input on the right, then 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 [Mac model] Microphone.
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. 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 does not appear if a 4-channel built-in microphone format is selected in Audio MIDI Setup, on a Mac with Apple silicon or on Mac models with an Apple T2 chip.
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.
