OptionalnocacheCache-busting query string appended to the resource URL.
OptionalwithForwarded to XMLHttpRequest.withCredentials. Set true so
cross-origin loads include cookies / auth headers (e.g. when
the audio is served from an authenticated CDN).
Optional settings applied to the audio resource load. The loader uses an XHR under the hood (via Howler), so the available knobs mirror what an XHR can be told to do.