If i have a function (void) X that takes an array of object in as a parameter and subsequently modifies said objects in the array, what will be the end ...

This post shows readers how to create an array in Java. Including: Array Lists, multidimensional arrays, maps, and more.

I haven't worked much with raw audio, but if you want to wrap a byte arrays and treat it as an array of floats, there are utilities in ByteBuffer (java.nio) to do that efficiently.