First off, OpenGL is only a graphics API, nothing more.
You really don't NEED additional libraries if you're planning on spending thousands of hours programming your lib (you'll need to work very low level (Probably make your own drivers), then more making it cross platform to work on other audio cards.
To do any kind of I/O, you need a library. Even I/O to the console (cin/cout) uses a library.. it just so happens that the library used in that case comes bundled with the language.
So to answer you questions: you need additional libraries. HOWEVER the libraries you need might be already be installed on your system. If you're on windows, for example... you probably already have WinAPI installed and can use its functions to play audio (this, of course, would mean your program would become Windows-only and would not be portable).