To activate "Mute" mode, decrease or increase the volume level of a Mac, you can press the function keys F10, F11 or F12 respectively. To activate and use the volume slider directly from the menu bar, you need to access the "Apple" menu, click on the "System Preferences" option, click on the "Sound" icon and select the check button "Show volume in the bar of the menus ". You can also change the volume level using the keyboard keys or the OLED Touch Bar.
Steps
Part 1 of 2: Enable Volume Control on the Menu Bar
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Step 1. Click on the "Apple" menu
It is located in the upper left corner of the screen.
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Step 2. Click on the System Preferences item
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Step 3. Click the Sound icon
If the option shown is not visible, click on the "Show All" button located at the top of the "System Preferences" window.
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Step 4. Select the Show volume check button in the menu bar
The button to adjust the volume level will be displayed on the menu bar. It features a stylized speaker cabinet.
Part 2 of 2: Adjusting the Volume Level
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Step 1. Click the Volume icon in the menu bar
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Step 2. Use the slider that appeared to adjust the volume level of the Mac
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Step 3. Click on a different device to change the sound source
On some Mac models you will need to hold down the ⌥ Option key while clicking the Volume icon to bring up the menu listing all audio input and output devices
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Step 4. Use the keyboard volume keys to adjust the level
Most Mac keyboards have the volume keys represented by the function keys F11 and F12. Use these buttons to adjust the Mac volume.
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Step 5. Tap the volume button located on the MacBook Pro Touch Bar
If you are using a MacBook Pro equipped with an OLED Touch Bar, you can display the volume slider on the screen by tapping the corresponding button on the bar. At this point use the slider that appeared to adjust the volume.