Here are two ways you can split a single audio file across multiple slides in Storyline 360:

Use the Built-In Audio Editor

One option is to import the audio file into all the related slides in Storyline 360, then use the audio editor to trim or crop the audio on each slide. Read this user guide to learn more about using the audio editor.

Use Presenter 360

If you need to split an audio file across numerous slides, you might find it faster to break it into individual tracks using Presenter 360, then import them into the corresponding slides in Storyline 360.