For anyone running into audio issues with Eschalon Book III in Windows using both DirectSound & FreeAudio, OpenAL is a 3rd option, and it is the only one I found to work for me on Windows 8. You can download it from here:
https://web.archive.org/web/20130629072 ... alinst.zip
It works just fine with both 32-bit and 64-bit Windows.