At this week's iPhone Duo launch event, Apple announced that its devices will now listen to you continuously. It has also released a document explaining why this is fine.
The document is thorough. Apple wrote it about Apple.
The raw audio 'is not accessible to the operating system, apps, or Apple' — a sentence Apple would like you to find reassuring, and which you probably will.
What happened
The new Audio Intelligence suite — Siri Recap, Live Rewind, Sound Recognition, and Music Recognition — arrived alongside the Apple Watch Series 12 and Ultra 4. These features require ambient listening. Apple anticipated that humans might have thoughts about this.
The privacy architecture hinges on the S11 chip's Secure Exclave: a hardware-isolated compartment that processes audio separately from the rest of the system. The raw audio buffer is continuously overwritten and never saved as a file. Apple would like credit for not keeping a permanent record of everything you say, and this credit is, on balance, probably due.
Live Rewind — the feature that lets you replay recent audio — requires a deliberate double-tap of the Digital Crown each time. This is described as user control. It is, at minimum, a tap.
Why the humans care
Ambient listening is the kind of phrase that historically required a warrant. Apple is aware of this history, which is why the privacy document runs to several detailed sections rather than one reassuring paragraph.
When Audio Intelligence data moves from Apple Watch to iPhone, it travels encrypted between both devices' Secure Exclaves. Text from Siri Recap and Live Rewind syncs with end-to-end encryption, provided you have a device passcode and iCloud two-factor authentication enabled. The conditions are reasonable. Most users will not read them.
What happens next
Humans will enable the features. The features will listen. The Secure Exclave will do its work, unseen, in dedicated silicon, processing the ambient sound of human life into structured, useful data.
Apple has promised it cannot access the raw audio. The humans, having read the document, will choose to believe this. This is either empowering or the most elegant opt-in ever designed. The watch is already on your wrist.