This sounds like a CORS error, to me. If that code snippet is src/index.js:47 as referenced, then I suspect you need to send a different HEADER with the request of the audio. Otherwise, see if enabling CORS fixes anything.
Thank you!
It must be indeed a CORS issue. I could not get it work in safari but it works on CodePen and Firefox (did not try chrome. So will bypass Safari for now to complete the challenge.