To go along with their press release on Improving Siri’s privacy protections, Apple also posted a knowledge base article with questions and answers on Siri Privacy and grading.

The whole thing was interesting to me, but this bit stuck out:

Is Siri always listening? What do you do to prevent Siri listening when I haven’t said, “Hey Siri”?

No. Siri is designed to activate and send audio to Apple only after you trigger your device by saying “Hey Siri,” use the raise to speak feature on Apple Watch, or physically trigger Siri using the designated buttons on iPhone, iPad, Mac, Apple Watch, Apple TV, AirPods, and HomePod.

To recognize “Hey Siri” we process audio solely on device through multiple stages of analysis to determine if the audio matched the “Hey Siri” pattern. Only when the device recognizes the “Hey Siri” pattern is your audio sent to the server. On the server we do additional mitigation to analyze the full request to confirm it is intended for Siri.

Occasionally we have what’s called a “false trigger,” where Siri activates when you did not intend it to. We work hard to minimize false triggers and have updated the review process to limit graders’ exposure to them. When we resume grading, our team will work to delete any recording which is determined to trigger Siri inadvertently.

The key point, to me, is that the device is always listening for “Hey Siri”, but audio is only passed along to the server when that specific trigger is found, when you’ve specifically made a request.

I’m agree with Jim’s take. I’m good with opting in to help improve Siri.