Apple has suspended human grading of Siri requests and began a thorough review of our practices and policies. Siri has been engineered to protect user privacy from the beginning. Apple will no longer retain audio recordings of Siri interactions. Users will be able to opt in to help Siri improve by learning from the audio samples of their requests. Apple sometimes uses the audio recording of a request, as well as the transcript, in a machine learning process that trains Siri to improve. Apple is committed to putting the customer at the center of what we do, which includes protecting their privacy.”]
Source: https://www.apple.com/newsroom/2019/08/improving-siris-privacy-protections/