What Bluetooth profiles are available for headphone connections on iPhone and iPad?
Isn't AAC a codec, not a BT profile?
Seems AAC is nested in A2DP - ref. Wikipedia
From the Apple documentation
https://support.apple.com/en-ca/HT204387
&quot;Advanced Audio Distribution Profile (A2DP 1.3)
This profile works with iPhone 5s and later, iPad Air and later, and iPod touch (6th generation) and later.&quot;
The technical specs for A2DP are available at bluetooth.org - https://www.bluetooth.com/specifications/archived-specifications/ --
A2DP v. 1.3 here
There's an interesting section in this article about Apple's M1 proprietary BT chip... https://www.howtogeek.com/338750/whats-the-difference-between-bluetooth-a2dp-and-aptx/
Also, maybe take a look at Apple Accessory Device Guideline Specs document here

specifically &quot;33. Advanced Audio Distribution Profile (A2DP)&quot;

Apple's proprietary-environment business model means they're probably keeping some info close to their chest so they can BEAT(s) out the competition (pun intended).