These files contain the audio support for iPhone. They are based on the CoreAudio audio driver for Mac OS X. The principle difference is that the iPhone doesn't seem to have a concept of audio devices ... it just has special units for audio in and audio out. Also had to change some functions to versions which seem to only exist on iPhone and will apparently exist in Mac OS X 10.6(!) There is currently no audio recording support -- my iPod Touch doesn't have a microphone to test this with.