Notice: Unity 2018.2 adds Audio Scrubbing support while editing. This can be enabled via the cog menu in the Timeline editor.

So from Unity 2018.2, it's recommended to use the Audio Scrubbing feature for audio preview while Timeline editing.

AudioPreviewTrack

AudioPreviewTrack is a custom track for Unity Timeline that allows instant audio playback in preview mode.

How to use

1. Add an Audio Preview Track to a timeline.
2. Add an Audio Preview Clip to the preview track.
3. Set an audio clip to the Clip property of the preview clip.

Known issues and limitations

• Audio Preview Track only works in Editor. It does nothing in built apps.
• Audio Preview Track only supports a single track. It doesn't work correctly if there are more than two playing tracks.
• Audio Preview Clip allocates small amount of GC memory per every frame :(

Nice! But how about having a waveform visualization?

Waveform visualization with the standard Audio Track has been implemented in Unity 2017.2. Try beta if you're interested.

Disclaimer!

I made this small utility just for making it easy to synchronize animation and music when creating a music video with Unity Timeline. Please don't expect that it's going to be more than just a utility. I used dirty and hackish tricks to implement it, so that it's not recommended for practical purposes.

If you seriously think that this functionality is a must-have in Unity, please give a vote to Feedback.

License?

Public domain