Rotate audio moves the sound across boxes automatically, so you can hear each stream in turn without clicking.
Click Rotate in the toolbar to turn rotation on or off using the saved settings. While rotation is enabled, hover over Rotate (or focus it and press ↓) to set the box numbers to include (for example 1 3 5-8, where 5-8 means 5, 6, 7 and 8) and the seconds each box keeps the audio. The numbers are the ones shown in each box's header. The Rotate switch shows whether rotation is enabled. Settings also appear when you turn rotation on.
Rotation only changes which box is unmuted. Alerts keep running on every box.