To do this, shut down your Mac and power it on again.
This happens because the computer restores your hardware’s default settings, and sets the internal hard drive as the startup disk. Reset it to clear any glitches with any of these and other attributes. Your Mac laptop uses nonvolatile random-access memory to store different settings such as sound volume, time zone, display resolution and recent kernel panic information among others, and access them quickly. If you find audio not working on your Mac laptop, try updating your operating system to the latest version and see if it fixes the audio issue.
Apple also improves and fixes audio latency, reliability of USB audio issues and other related user concerns. Each time a new macOS is released, it not only comes with improvements and new features, but also changes in audio drivers, kernel frameworks, Unix tools, new bugs and sometimes audio issues follow.
