Sound (System Preferences)

The Sound panel of System Preferences provides access to basic audio input / output controls of a Macintosh computer running Mac OS X or macOS.

Options
General controls allow setting of the sound output volume level, and adding the volume control to the menu bar. Tabs provide access to more specific controls.

Sound Effects
The sound effects tab allows the user to select the system's default alert sound, and select the sound output device and volume level for such alerts. Additional options include user interface sound effects. Alert sounds are stored in:
 * (for all users)
 * (for the user only)

Output
The Output tab allows the user to select a device for sound output, such as:
 * Internal Speakers (built-in)
 * Line Out (headphone jack, if available)
 * Digital Out (optical digital-out port, if available)
 * Monitor outputs (through DisplayPort, HDMI, Thunderbolt, etc., if available)
 * Wireless outputs (AirPlay devices, AirPort Express, HomePod, or third party options, such as AirParrot)

Input
The Input tab shows the selected input volume level, and allows the user to select a device for input output, such as:
 * Line In (headphone jack, if available)
 * Digital In (optical digital-in port, if available)
 * Wireless input (AirPlay sources, or third party options, such as AirParrot)