Check your sound settings
First, disconnect any cables from the USB, Thunderbolt or 3.5mm audio ports on your Mac.
- From the Apple menu , choose System Settings (or System Preferences).
- Click Sound.
- Click the Output tab, then select the built-in speakers. If you can't see built-in speakers as an option in the Output window, contact Apple Support.
- If the Output volume slider is set low, move the slider to the right and test again.
- If the Mute box is ticked, untick it and test again.
- If you still can't hear any sound, contact Apple Support.