Apple will no longer retain audio recordings of Siri interactions by default. Instead, the company will continue to use computer-generated transcripts to help Siri improve. Apple will allow users to opt-in to having their audio recordings listened to by human reviewers to help improve Siri’s responses. If you opt in to the grading program, only Apple employees will be allowed to listen to audio samples of your Siri interactions, rather than third-party contractors. At least 300 contractors in Europe who were part of Apple’s grading program have lost their jobs as a result of these changes.
Source: https://thehackernews.com/2019/08/apple-siri-recording-privacy.html