The volume control plugin allows you to control the player volume using mute/unmute buttons and a volume slider.

This demo demonstrates Volume Control options:

For regular player usage, use the up and down arrows to control sound during playback.
Volume change step can be set using the keyboardShortcuts plugin volumePercentChange property (default is 0.1)

For accessible screen reader usage, turn on the accessibleControls flag of the volumeControl plugin.
This enables using the TAB key to navigate to volume control and the SPACE key to change the volume.
Accessible volume change step can be set using the accessibleVolumeChange property (default is 0.1)