RAW audio files

I extracted audio files from Heroes IV video game. But they all RAW and every file has own format: some 8-bit, some 16-bit unsigned, some 16-bit signed big-endian. Are there a way to guess audio format from content? Preferably non-calculus based.

That's an interesting problem. The only thing that comes to mind for me is to have an ideal of an acceptable range of values for the frequencies in the audio, and then calculate some of the approximate frequencies prevalent in the audio clip, when interpreting the clip as of various formats, and then selecting the format that yields the most reasonable frequency range.