Yup, the list of supported formats includes audio files (.mp3, .wma, .wav, .flac, .aac, .m4a, .ac3). You upload it exactly the same way as video files.
You can optionally include an image too, or just upload audio with a blank screen. There's also a planned "zero pixel" upload in the future, where there would just be the audio and no screen at all.
Some channels are just podcasts with the podcast's artwork as an image.(for example https://media.privacyinternational.org/c/podcast/videos).