I'm baffled as to why you think that counts as a source.
I mean, just Google it. Microphone hacking is a thing. (Edit: You know what, Let me Google that for you.)
I only felt obligated to grab a link grabbed because folks keep repeating the misinformation that "no one is hacking your phone microphone, or it would be in the news". It's just not news anymore.
Android and iOS malware will try to grab stuff off of your microphone.
It's not a conspiracy theory. It's not news.
Malware actors do malware things, and sell whatever they can harvest.