Converting audio to CAF format for playback on iPhone using OpenAL

I am using the SoundEngine sample code from Apple in the CrashLanding sample to play back multiple audio files. Using the sample caf files included with CrashLanding everything works fine but when I try and use my own samplesconverted to CAF using afconvert all I get is a stony silence ;)

Does anyone have settings for afconvert that will produce a CAF file capable of being played back through OpenAL?

afconvert -f caff -d LEI16@44100 -c 1 in.wav out.caf

References:

• Apple's Multimedia Programming Guide: Using Audio: Preferred Audio Formats in iOS
• afconvert(1) man page (use afconvert -h for complete info)