So the current JavaScript implementation of OpenAL for HTML5 is not stable, it lacks certain features like the doppler effect, pitch modification and changing the speed of sound. On Chrome it crashes with an error “missing function panner.setVelocity”. Different browsers have slightly different underlying audio API.
But sooner or later these issues will be resolved. I believe I can supply my own OpenAL wrapper as a JavaScript library, that would be the next step.
In the meantime, I’ve updated the extension source code on github and you can try HTML5 support for yourself.
Open in Firefox or Safari. https://lerg.github.io/extension-openal/