They're on an proprietary extension of Bluetooth, standard compatible but closed to their devices. They usually don't talk much about it, Phil Schiller was the most explicit I think (it was about the airpod's W1 but it's the same deal)
https://www.theverge.com/2016/9/7/12829190/apple-w1-chip-iph...
> Apple’s Phil Schiller described Apple’s move to a new wireless chip as “fixing the challenges” of wireless audio
They're on an proprietary extension of Bluetooth, standard compatible but closed to their devices. They usually don't talk much about it, Phil Schiller was the most explicit I think (it was about the airpod's W1 but it's the same deal)
https://www.theverge.com/2016/9/7/12829190/apple-w1-chip-iph...
> Apple’s Phil Schiller described Apple’s move to a new wireless chip as “fixing the challenges” of wireless audio