On your Mac, choose Apple menu
To access your System Settings, click on the 
symbol (located in your dock, or click on the Apple symbol on the upper left corner of your screen, then select 'System Settings'.
Audio (Input - Microphone)
You can use your computers and turn on microphone, your display's microphone (if it has one), your iPhone microphone, or an external microphone plugged into your computer sound port.
Note: The Recording Indicator 
in Control Center 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 options in Sound Settings.
1. On your Mac, choose Apple menu 
in the sidebar. (You may need to scroll down.)
2. 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.
3. 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.
Audio (Output - Speakers)
You can play sound through your computer's internal speakers, your display's speakers (if it has speakers), or through speakers, headphones, or other equipment plugged into your Mac or available wirelessly through AirPlay.
1. On your Mac, choose Apple menu > System Settings, then click Sound in the sidebar. (You may need to scroll down.)
2. Click Output on the right, then select the device you want to use in the list of sound output devices.
All sound output devices available to your Mac are listed, including the computer’s internal speakers, devices plugged into your computer’s sound port (
), USB speakers, and AirPlay devices.
For any device plugged into the computer’s sound port, choose Headphones.
3. Do any of the following to adjust your sound output settings:
-
Adjust the volume: Drag the Output volume slider.
If you have Sound in the menu bar, you can turn the volume up or down from anywhere.
To set a volume for alert sounds, drag the Alert volume slider in Sound Effects. The alert volume is relative to your computer’s volume, so if you lower the computer’s volume, alert sounds also play more quietly.
- Stop sound output: Select the Mute checkbox.
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Adjust the balance: Drag the Balance slider.
Depending on your Mac and the devices you use, you may be able to set other volume options using the Audio MIDI Setup app.
If you use apps that have volume controls (for example, Music or iMovie), their settings can only be equal to or less than the computer’s output volume. They don’t override what you choose in Sound settings.
Video (Camera)
Some apps you install can use the camera on your Mac to take photos and video. You can decide which apps are allowed to use the camera.
1. Choose Apple menu > System Settings, then click Privacy & Security 
in the sidebar. (You may need to scroll down.)
2. Click 'Camera' on the right (If you don’t see Camera, upgrade to macOS Mojave or later).
3. Turn access to the camera on or off for each app in the list.
The list shows apps you’ve installed that have asked to use the camera. If you turn off access for an app, you’re asked to turn it on again the next time that app tries to use the camera.
If there are no apps in the list, you haven’t installed an app that uses the camera. FaceTime, Photo Booth, and other apps that come with your Mac automatically have access—you don’t need to give them permission.
Note: The camera automatically turns on when you open an app that can use the camera. A green light beside the camera glows to indicate the camera is on. The camera (and the green light) turn off when you close or quit all apps that can use the camera.
For Additional Help:
Apple Support: If you can’t hear sound from your Mac speakers
Apple Support: If the built-in camera isn’t working on your Mac