Gary Geaves is the Vice President of Acoustics at Apple and his team was largely responsible for the design of AirPods. He talks about them in an interview (via What Hifi).
Gary Geaves AirPods Interview
Here are a few highlights from the interview.
AirPods Gen 3:
We started with looking very closely at the strengths of the original AirPods, and we know many people really like the effortless open fit that doesn’t stick into your ear canal and rests comfortably on your ear. That doesn’t create a seal, which is what people like, but it creates challenges for the audio team.
Spatial Audio:
And these are quite complex, difficult measurements to do – we’re measuring the sound, the response or your ear to a speaker in multiple different directions – and we really did that so that we could come up with the best HRTF that works for everyone, which is again very easy to say and not easy to do.
Bluetooth:
…we have to concentrate very hard on squeezing the most that we can out of the Bluetooth technology, and there’s a number of tricks we can play to maximise or get around some of the limits of Bluetooth. But it’s fair to say that we would like more bandwidth and… I’ll stop right there. We would like more bandwidth.