As always Bob, an excellent explanation, nice one; I'll just add that the word you are looking for is codecs.
Codecs are software fragments (code & algorithms) that operate in two parts: encoding and decoding data. In audio you have .wav .mp3 .aiff etc. Picture files you have .png .jpg .gif etc. And video you have .mp4 .mov etc.
When you go to save a picture or some music or video in a digital format on your computer, you use a codec - and most people use them without even thinking about it.
Each device an AKP chip is installed in will come bundled with software to "decode" the audio file format. Some codecs include compression, such as mp3, and some are lossless, .wav or .flac. The point is it will all be handled by whatever device sorts playback before getting to the AKP chip. All the big consumer electronics firms have licenses to use the standard codecs.
Interestingly the headphone may have to work slightly differently if the intention is to plug it into a 3.5mm jack, as that usually sends an analog signal to a headphone driver. So AKP headphones may need to encode the analog signal into a digital one to play - in any case, it's not a big deal.
It's getting exciting Good luck all.
AKP Price at posting:
$17.05 Sentiment: Buy Disclosure: Held
(20min delay)