Sorry about bumping this ancient post 
, but I’ve recently really needed this and I’ve put together a nice little endpoint.
Example
https://api.hyra.io/audio/9044425900
Short and sweet documentation
https://api.hyra.io/audio/:AudioID
Simply take the Audio ID from the Library and put into the URL. The Roblox sound will then be accessible to play in the browser, download the file or parse.
Hope this helps! 