Idea HN: Uninterrupted audio playback (even when I leave a website)

All too often I'm scrolling though a website (most often a blog) click to play a piece of audio or video (music, podcast, etc) and carry on scrolling. Without thinking I press 'next page' or close the website all together whilst the media is playing in the background. I then have to either go back a page or re-open the tab.

I'd like an extension for my browser that realises that I've left the page but keeps on playing the audio (or video) uninterrupted in the background.