Doesn't work for me in Chrome Beta or Canary I'm afraid, unless I reload the page which is probably not intuitive for many users.
What I've been doing is sending a pop-up to users on audio-critical pages (where audio is the entire point of the site) that says "hi, let's get started, you'll hear audio on this page so please adjust your headphones or speakers" and that seems to give the best result. It's also helpful on a page like yours where the sound is quite loud and I found it a bit loud for my headphones. You must also just provide a button that changes the sound volume which would have the same effect, of telling Chrome that the user has interacted with the page.
What I've been doing is sending a pop-up to users on audio-critical pages (where audio is the entire point of the site) that says "hi, let's get started, you'll hear audio on this page so please adjust your headphones or speakers" and that seems to give the best result. It's also helpful on a page like yours where the sound is quite loud and I found it a bit loud for my headphones. You must also just provide a button that changes the sound volume which would have the same effect, of telling Chrome that the user has interacted with the page.