Why is PerfPowerServices using my microphone?
This question has already been asked by cisforcojo in https://discussions.apple.com/thread/251424972 on Jun 3, 2020. Unfortunately that thread cannot be replied to and instead suggests to "ask the question again to resume the discussion". I am not sure how much sense this makes.
Like the original author I also use the app OverSight which uses a configurable rulebase to determine which processes will be allowed to use the microphone or camera. Since I updated to BigSur, Oversight has notified me that the suspicious process from the original post (/usr/libexec/PerfPowerServices) has made my microphone active. Even worse, it does so although there is no matching OverSight rule which would usually be required.
2021-01-03 02:20:50 +0000: Audio Device became active (Built-in Microphone, process: PerfPowerServices, /usr/libexec/PerfPowerServices)
I was not awake at that time so I can safely say that this happened while the Mac was on standby.
I would appreciate if you Apple guys could elaborate a bit on what might cause this behaviour which seems double-sketchy. However the issue might also be with OverSight.
macOS 11.1
Mac mini, macOS 10.12