Audio and Sound Edits Needed

I've created a learning course that needs some video and audio edits before it gets approved to go on the learning platform. Here is a list of the changes that need to take place with my videos before they get approved. 1. The audio quality for your promo video is currently affected by low volume. Low quality audio in a promo video can turn some students away. In order for your course to be approved, please fix this audio issue. Please see this article for more suggestions on improving your audio quality. 2. It seems that your video in lecture 4 and 6 are in mobile view. Would you be able to add a lighter background color instead of black so that it will look like in 16:9 widescreen aspect ratio. 3. For lectures 2, 3, 4, 6, 7, 8 the audio seems to have some background noise that will need to be improved before we can move forward. Bad audio can cause students to have a distracting course experience when trying to understand the concepts you want them to learn. In a nutshell. Audio volume needs to be improved. Background noise needs to be cancelled out. Lighter background color for the two mobile view videos.