In Vidyard, you can upload audio only files when this feature has been enabled in your group. This could also be suitable for podcasts.
The default settings will show an audio visualization during playback, which can be a customized color that matches your brand.
This visualization may not be something you wish to show. If this is the case, there is an option to change it to be the thumbnail of the player instead.
The steps in the video below will guide you through the process (no sound).