Let's say your first user experience with Siri took place approximately eighteen months ago. You may not even remember what you asked of Siri in those early days of experimentation with the service. But there's a good chance that Apple does.
From questions to commands, everything that users put into Siri remains with Apple for up to two years. That's not a guess or a rumor. That's an admission straight from Apple, which confirmed today that anonymized user data is retained for approximately 24 months.
As of this writing, Siri itself isn't yet 24 months ago, as the feature was only made available to iOS users in late 2011.
To be perfectly clear, here's what Apple spokeswoman Trudy Muller says: “Apple may keep anonymized Siri data for up to two years... If a user turns Siri off, both identifiers are deleted immediately along with any associated data.”
Whenever you speak into Apple’s voice activated personal digital assistant, it ships it off to Apple’s data farm for analysis. Apple generates a random numbers to represent the user and it associates the voice files with that number. This number — not your Apple user ID or email address — represents you as far as Siri’s back-end voice analysis system is concerned. Once the voice recording is six months old, Apple “disassociates” your user number from the clip, deleting the number from the voice file. But it keeps these disassociated files for up to 18 more months for testing and product improvement purposes.