Sound/Audio API
Audio API works in a similar way to Graphics API, except instead of becoming lower frame rate, it just gets worse in quality, an audio api processes and synthesizes audio, mainly meaning it just produces audio.
Java Sound API
Java sound API is pretty bad at effecting and controlling audio input and output, It gives the user direct and unfiltered control over the capabilities usually needed for audio input and output. On Java as a platform, Java Sound API gives you the lowest level of audio support, but over audio specific functionality it gives you the most control, it does not go into the super high tier, hard to do and complex parts of sound editing, it provides a base. In other terms, Java sound API is good at helping you create and form a base, but wont be able to help when it comes to the complex and sophisticated tasks Java Sound API just can't deal with it.
OpenAL
OpenAL works a lot like OpenGL, but for sound instead, so It's platform independent and a good all round sound API to fall into the middle of the pack in terms of how good it is, it's like the medium that everyone can use, that is not bad, but not amazing, which makes it a prime candidate for the most used Sound API by everyone.