Did you know that you can set up a proxy from your phone and capture all traffic from it? It would be so trivial to find the traffic from your phone. There are ways to MITM and inspect the traffic, too.
There are also many people doing static reverse engineering of phone apps looking for security vulnerabilities. To believe this urban legend, you’d also have to believe that none of them have ever encountered this hidden voice analysis code.
If we ignore that, you know there are OS-level security controls on apps, right? iOS and Android don’t make it easy for apps to use the microphone constantly and run in the background to process it.
Finally, if we ignore all of that, how can anyone believe that these companies are recording conversations but none of their employees have ever chosen to blow the whistle? We’ve seen numerous FAANG “whistleblowers” come through with everything down to trivial or baseless complaints, but nobody has blown the whistle on these supposed widespread spying programs?
The whole urban legend is preposterous to anyone who has any experience with apps or phone security, let alone common traffic analysis or reverse engineering tools. I don’t understand why the myth is so persistent among even some technical people.