Audio File Matching Program

Question

than can take two audio files (e.g. WAV) as inputs, compare them, and spit out a number that tells you how similar the audio files are.

Answer 1

That depends on what does this number actually count. What you are trying to do there looks more like an AI rather than programming. For example:

What you could do is storing every single character of both files on a string. Then counting which of the characters on the first string are matching the characters on the second one. You will get a number 'n' out of that. Afterwards you could take the length of the largest string 'l' and compare it to 'n' to get the percentage: p= 100*n/l %

But there are other ways to compare the 2 files too. For example instead of comparing n to the largest string, you could compare it to the shortest one or to the avarage of the 2 lengths. Or when comparing them to get the 'n' how are you going to do it? equal elements must be on the same position? equal elements don't have to be on the same position but still have to be in a row? equal elememts could be at completly random positions?
These are just some examples. It is you who desides how to write a program that does that