But I don't want to make replacement API? I'm just expecting these API to be freely available on any OS, you can't seriously say that you will charge for these.

But I don't want to make replacement API? I'm just expecting these API to be freely available on any OS, you can't seriously say that you will charge for these. It's not an "SDK" but basic OS primitives. I doubt Apple can even ship a mobile phone without audio or I/O support even without third party apps...