This is a collection of functions (partially borrowed from somewhere else) for Processing.
They can be used to read a wave file, convert the content to arrays or save an array of values froim -1 to 1 to a wave file (in the form values[channel][sample]).

https://github.com/Morusque/p5WaveReaderWriter

Now I have to say I don't understand why I always have to code these things by myself.
In several languages over the years I could find many libraries to play audio files, analyse them in realtime, apply predefined effets etc...
But almost never to simply handle the reading/wrinting part and let you manipulate the data as arrays to do whatever you want to do with it.