To bring in audio, you must be running 3.7, which is currently in beta (check the beta checkbox in the settings and restart). Set the path on the Audio
node so your audio files show up in the tree under it, then click a file and create a new audio event. Now go to animate mode and set a key for that audio event when you want the audio to be played.
It currently isn't possible for the dopesheet to show seconds. However, you can change the dopesheet framerate on the Playback
view (alt+P
in animate mode):
Playback - Spine User Guide: Dopesheet FPS
For example, you could set it to 100, so you get 100 frames per second, which might help you match up to the timestamps in your audio. It's currently limited to 120, but we could raise it to 1000 if you wanted to match it up with milliseconds. Note you should set the dopesheet framerate before you start setting keys, and know that it affects all animations.
The dopesheet framerate is solely to split time into uniform chunks to make it easier to align keys. You can hold shift
while dragging the timeline or while dragging keys to position them between dopesheet frames.
Edit: In 3.7.43-beta the dopesheet FPS can go up to 1000 and the timeline zoom range is adjusted based on that.