Actually, Contractors were assigned the job of listening to Siri recordings and grading them. They ended up hearing people having sex, drug deals and business talks in over 1,000 recordings observed by them.
An Apple Employee confirmed they would hear the recordings of personal data occassionally. He, however, assures details of every Siri User will be kept anonymous.
Last month, A Whistleblower exposed how Apple Contractors have been hearing the conversations of the Siri Users. Following which, Apple suspended the programme, which include transcription and grading work, with immediate effect citing customer privacy is its priority. Siri Grading has been suspended globally after an Ex-Employee leaked that workers listen to conversations and were even graded based on various factors.