According to media reports, Apple began to provide developers with AirPods Pro Beta firmware in July to test its new features before release. Recently, Apple officially released the AirPods Pro Beta 2 firmware (4A362b).
According to Apple's developer website, the AirPods Pro Beta 2 firmware update adds support for Conversation Boost (call enhancement), a missing feature in the Beta 1 beta.
Conversation Boost (call enhancement) is a feature of iOS 15. It uses the beamforming microphone in AirPods Pro to increase the volume of calls, which is very helpful for those with mild to moderate hearing impairment.
AirPods Pro Beta 2 firmware can now be downloaded from the Apple developer website under the "More Downloads." To install the beta firmware, users must have an iPhone with iOS 15 beta software, a Mac with Xcode 13 beta software, and a fully charged AirPods Pro.
Once installed, there is no way to roll back to the non-beta version of the AirPods Pro firmware. The only option is to turn off any updates and wait for the release of the non-beta version.