Found something mildly interesting playing around with this. One of the network requests when you ask for audio is this: https://www.google.com/js/bg/Kv2WsNzHE5GULL-TmjqX5N4dnwt4D3c...
Which presents this, in a comment at the top of the returned js:
Anti-spam. Want to say hello? Contact (base64) Ym90Z3VhcmQtY29udGFjdEBnb29nbGUuY29t
That decodes to: botguard-contact@google.com