My understanding gleaned from reading a Verge article about AirPods Pro is that the latest version of the firmware is 4A400. That firmware provides a Custom Transparency Mode in Apple's headphone option for Conversation Boost. When Conversation Boost is enabled, the AirPods Pro isolate voices above any background noise and any other conversations. In essence, when Conversation Boost is enabled it allows better sound of the human voice in a noisy situation. That mode seems like it would help my hearing people talk in otherwise noisy situations. However, an article about Conversation Boost by Ian Carlos Campbell (@soupsthename) published in the Verge on Oct 6, 2021 states Conversation Boost is only available if the AirPods Pro are running firmware 4A400. As to firmware updates, the article states "Unfortunately, there's still no manual way to force an update on your [AirPods Pro]." I tried to update my AirPod Pro's firmware from 4C165 to 4A400 to accommodate Conversation Boost using Axel F.'s suggestion posted in the Community on Dec. 23,2021, but it did not work. Thus, I have concluded that Vulture is correct and that firmware updates or at least this one cannot be done manually. It appears that if I want Conversation Boost, I am going to need to purchase another pair of AirPod Pros with the later firmware already installed. I am disappointed in the lack of updatability of my AirPod Pros, as I have owned them only a month and a half.