Depending on the display location, visual-only information is just exactly what you need.
What is the use of audio in a crowded place, such as a train station or a busy avenue? Probably not much but additional noise which does not add up to your Campaign’s content. For those devices located in busy areas, simply adjust the Player settings to mute them.
If you need to mute a cluster of devices, you can also apply this same setting to a Player Group.
Furthermore, you can also mute Players over your whole screenpublishing account: