Someone who just reads from slides works just as well with the screen off. Think about the last time you let a video play only for the voice. The picture did nothing, yet it kept your screen lit and your data running. That is why many people look for a quick way to download a YouTube video as an MP3 file.
This guide shows how the MP3Paw converter fits your needs, how to prepare your link for a clean result, and what to do with the MP3 file once it's saved to your phone.