How to uncheck mute on macbook air 2011 - Apple MacBook Air

Did you try searching before asking? MacBook Pro 13 Unibody Early 2011 Battery Replacement

Try quitting some unused applications > Apple Menu> Force Quit > select open applications > and quit.
Another way is to restart the Macbook. Make sure you uncheck "Reopen windows when log back in"

sound drivers need reinstalling if under warranty then take it to the apple store

Turn off letting the Hard Drive Go To Sleep when Possible.

It's in
Apple menu
System Preferences
Energy Saver
1st check box should be unchecked.

Press the mute button again. If that doesn't work, then press the volume-up button until you can hear the popping noise of the volume adjustment.

What I did to connect to BOSE wireless speaker to my MacBook air was go in advance settings and uncheck all three options there and then press the wireless button until it beeped--> then I was able to pair it to my laptop. Success!

Unmute your speakers by pressing "F10".

Apple menu (top left) System Preferences > Sound > Output tab select the Internal Speakers
check your output volume and make sure the Mute checkbox is unchecked.
Plugin a pair of headphones. If you still have no sound. The sound board needs to be replaced, which is attached to the logic board. Meaning the whole logic board needs to be replaced.

Go to your system preference panel in the dock... click on the sound control icon. Look down at the bottom of the dialog box... there is a "MUTE" check box....make sure it's unchecked....
Also press the 'fn' key at the bottom left of your keyboard while pressing the f5 key... to raise volume...
let me know if that solves the silence!
K

Actually your speakers are MUTE by now from that control. Hey simply just Uncheck the checkbox on that control and then this symbol will disappear and u will start hearing voice...enjoy... rate this solution if it is really helpful to you