What is the Apple H2 chip?

Which AirPods have the H2 chip? What does the H2 chip do?

Apple H2 audio

The Apple H2 was introduced in September 2022. This Apple silicon supports Bluetooth 5.3 and is featured in the AirPods Pro (2nd generation) launched the same year. The chip uses adaptation algorithms to quickly process sound, rendering audio for your specific ear shape in real time.

The H2 chip works with Apple's custom driver and amplifier to reduce distortion and deliver crisp highs along with deep bass. With the H2, input from noise-cancelling microphones is detected and countered to provide up to two times more Active Noise Cancellation than the first generation AirPods Pro. The H2 hardware is capable of reducing noise at 48 kHz, which is 48,000 times per second.