Audio is scheduled through the same playlists as everything else: add it, and schedule it to the right screens at the right times.
It suits the cases where sound carries the message and a picture supports it. A safety procedure playing while the steps are shown. A shift announcement that fires at a set time with nobody starting it.
Formats
MP3 at up to 320 kbps, and FLAC.
Duration
Like video, audio plays for its own length. You do not set a duration.
What is on screen while it plays
Put something visual in the same playlist. Audio on its own leaves the display showing whatever came before it.
Where the sound comes out
HDMI by default, so it goes to the display’s own speakers. To send it to an amplifier or ceiling speakers instead, switch the screen to the 3.5 mm jack.
That is a per-screen setting, not a per-item one. See Video and audio output.
Silent by design
If a screen is in a space where sound is not wanted, the reliable fix is the display’s own volume or mute rather than the content. A screen muted at the panel stays muted whatever plays on it.