What is coreaudiod?
coreaudiod runs Core Audio, the system that handles every sound on your Mac: playback, microphones, headphones, AirPods and audio interfaces. Apps send their audio to it and it mixes everything for your output device.
Playing music or joining a call uses a little CPU. Heavy or constant usage usually points to an audio app, a virtual audio device, or a glitch.
Why is coreaudiod using so much CPU?
- Audio-heavy apps like music production software or several call apps at once.
- Virtual audio devices installed by recording, streaming or call apps.
- Bluetooth headphones switching modes, for example when a call starts.
- A glitch after sleep or after switching devices, sometimes with crackling or no sound.
How to fix high coreaudiod CPU usage
- Confirm it in Activity Monitor. Press ⌘ Space, type Activity Monitor, open the CPU tab and sort by % CPU. Watch
coreaudiodfor a minute: short spikes are normal, only steady high usage needs fixing. - Quit audio apps you aren't using, including call apps running in the background.
- Check your output and input devices in System Settings › Sound.
- Restart Core Audio if sound is stuck or crackling: open Terminal and run
sudo killall coreaudiod. It restarts automatically within a second. - Remove virtual audio drivers you no longer use, using their app's own uninstaller.
More help: How to check CPU usage on a Mac