Once the javascript is loaded into the phone via web browser, my understanding is that the only steps left is direct connection to audio jack from the web page

Once the javascript is loaded into the phone via web browser, my understanding is that the only steps left is direct connection to audio jack from the web page that is loaded into the browser. Certainly there are implications that this data (once generated by the browser) could be retransmitted over the web to some remote hardware, but it's not critical to get this to work.