Thank you for replying so quickly and sorry for reviving a relatively old thread, but the issue of sound not playing on Android and iOS (at least until version 5 - didn't have the time to try it yet) is still there as of now, so I thought that it was ok to reply here.
Nevertheless, please feel free to move my post to a new thread if you deem it necessary.
Regarding the royalties issue, I am conscious it concerns only me (or any other game publisher) - not you - and that is why I am asking for the freedom to take this risk!
With that said, I have found a quick and (very) dirty workaround to play any sound format supported by the browser, but not available in C2 as an export format (*):
On some condition, go to sound file url in new window -> alert "something" on the main window, so that the user doesn't leave the main window.
Works with both file:// and http:// protocols in Chrome, provided you choose the corresponding preview mode and popup blocking is disabled in the browser.
Didn't try it yet on Android's mobile version of chrome, but it should definitely work, although I would not recommend using such a trick in production, due to obvious aesthetic reasons...
Support for Iframes would be a much more elegant way of achieving the same goal - could it be a "politically correct" solution to enable this (and way more)?
Also, can we somehow use the existing ajax object to play remote sound files in any browser-supported format?
(*not necessarily mp3, as wav is also in that case and might be useful for enabling small sfx files to play on iOS)