Once you join the Acast's marketplace, ads are dynamically inserted into your episodes. Based on when and where your listeners press play, ads are “stitched” into your audio file and served as a seamless part of the listening experience.
Because ads are delivered dynamically, it’s helpful to understand how their loudness compares to your own audio levels — especially if you want your show to sound consistent from start to finish.
How Loud Are Acast Ads?
All Acast ads are normalized to -18 LUFS, which stands for Loudness Units relative to Full Scale. LUFS is a more accurate way of measuring how loud something feels to listeners, rather than just its volume. Normalizing ads to -18 LUFS helps maintain a consistent loudness level across all ads served through the marketplace.
What About Sponsorships?
If your show is selected for a sponsorship, you may be asked to record a custom message on behalf of a brand. These messages are also dynamically inserted into your episodes — but unlike regular ads, sponsorship messages are not normalized. They’re used at the same loudness level you submit them to the Acast sales team.
To keep your show sounding consistent, we recommend matching your sponsorship recordings to your regular episode levels.
Why Do Acast Ads Sound Louder Than My Show?
If your podcast episodes are produced at a lower LUFS value (for example, -20 or -23 LUFS), the ads may sound louder by comparison. This is a common reason why some hosts notice a jump in volume when ads play.
Most audio editing tools — like Audacity, Adobe Audition, or Descript — allow you to check and adjust your LUFS level. If you want a smoother listening experience, consider mixing your episodes to around -18 LUFS, which will bring your content closer to the loudness level of Acast’s ads.