When you create audio content for Alexa, whether for a flash briefing feed or for another custom skill, it's important that your audio content plays at a loudness level consistent with Alexa's voice. Audio clips should play at a consistent level without fluctuations in the sound. If you have ever watched television, and had a commercial play at a much louder level than the other content, you have experienced how disruptive an inconsistent loudness level is. If your audio clips do not play at a level consistent with the guidelines, you skill may not pass certification