Storyline Audio Options

Hi community.

I am trying to figure out if there is a way to do the following using Storyline files:

1. Add silence across multiple slides or scenes without having to add one at a time. Is there a way to do this in Storyline?  Note, the slides or scenes are different lengths/timings
2. This will probably be outside of Storyline- Is there a way to export storyline or audio files and then remove background noise?

Thank you in advance!