I was using .wav files under Windows in the Simulator and everything worked fine. Since some of the wav files are rather large I decided to convert them to a compressed format for my iPhone/iPad release.

According to the documentation, I should shy away from CPU intensive formats like MP3, so I converted the files to .m4a format per the suggestion in the docs.

However, when I try and play the sounds on the iPhone or iPad I get nothing. If I switch back to wav files they play fine, but take up a lot of memory.

Can we get some documentation on what audio formats are supported for iOS devices?

I'm using build 591 so if this was a known issue and has been fixed in a daily build then let me know and I'll grab the latest.

m4a should work unless you picked a copy-protected format or some weird settings. Most problems are usually that the file was not converted to the correct format in the first place.

iOS and Mac use Core Audio to decode and they support a lot of formats.
m4a is usually an audio mp4 which is usually related to aac, which should work.

We already have documentation here:
http://developer.anscamobile.com/reference/index/audioloadsound-0
http://developer.anscamobile.com/partner/audionotes

Implied in the audio notes page, you should also note that m4a is also a CPU expensive format to decompress.

If you want more info on audio files and formats, watch:
http://www.youtube.com/watch?v=6QQAzhwalPI
at 14 min 12 sec