Audio files can be added to a lesson. The following types of audio files can be added: .aac, .aiff, .m4a, .mp3, .mp4, .wav.
To add audio to a lesson, select the music note icon from the toolbar. It is titled "Add Audio."
Select the button titled "Select Audio from Local Device." This will open a window similar to a "file open" dialog. Browse to and select the audio file to upload and select Open.