If you can’t hear sound from your Mac speakers
First, make sure any volume controls in the app you’re using aren’t turned all the way down. Also, try playing a different audio file, CD, or DVD, or try playing the file or disc on another computer or media player to isolate the problem. Then, try the following solutions.
If you’re using your computer’s built-in speakers
Unplug any headphones or external speakers.
On your Mac, choose Apple menu
in the sidebar. (You may need to scroll down.) Click Output. Make sure [Mac model] Speakers is selected, the “Output volume” slider is not all the way to the left, and the Mute checkbox is not selected.
If you’re using external speakers connected to the audio output port of your computer or display
Make sure the speakers are plugged into the audio output port on your Mac or display, and if necessary, into a power supply. Check for a power switch and volume adjustment on your external speakers. If necessary, turn the speakers on and adjust the speaker volume.
On your Mac, choose Apple menu
If your external speakers still aren’t working, check the instructions that came with your speakers.
If you’re using external speakers connected to the USB port of your computer or display
On your Mac, choose Apple menu
Click Output, then make sure the external USB speakers are selected.
Press and hold Option, then choose Apple menu > System Information.
Click USB in the Hardware section of the sidebar, then make sure your speakers are listed. If they aren’t, try unplugging the speakers and then plugging them in again.
If your external speakers still aren’t working, check the instructions that came with your speakers.
If you’re using your display’s built-in speakers
Unplug any headphones or external speakers from your Mac.
Make sure the cables from the display are connected to the ports on your Mac.
On your Mac, choose Apple menu
If you’re using a digital receiver
If you’re using your computer’s digital output port (not available on all computers), choose Apple menu
Make sure your computer is connected to a digital-ready receiver using an optical digital cable, and that your receiver is set up for digital input (see the information that came with your receiver).
Try adjusting the volume on your receiver. You can’t use the computer’s volume controls to adjust the volume while using digital output.
If you’re not hearing sound for specific alerts, see Change the alert sounds. For information about the audio ports on your Mac or display, see Use the ports on your Mac.