The SoundAsset descriptor — logical name,
src base path / prefix (or data URL), and optional playback
flags (autoplay, loop, stream, html5).
Optionalonloadcb: () => voidCalled when the resource has finished loading.
Optionalonerrorcb: () => voidCalled when loading fails.
Optional LoadSettings — nocache (query
string appended for cache busting) and withCredentials (forwarded
to the underlying XHR for cross-origin authenticated requests).
The number of assets loaded (always 1 on success).
Load an audio file.
sound.srcis treated as a base path / prefix; the URL is built as${sound.src}${sound.name}.${ext}for each extension configured by init, until one loads. Data URLs (data:audio/...) are used as-is and skip the prefix-and-extension dance.