Read the Apple document explaining how new listening features still protect your privacy

The S11 chip in Apple Watch Series 12 and Apple Watch Ultra 4 includes a Secure Exclave: a hardware-isolated compartment built into the silicon to process sensor data separately from the rest of the system. Data that is processed and analyzed in the Secure Exclave cannot be accessed by watchOS, apps, the user, or Apple. Audio from the microphone enters the Secure Exclave of Apple Watch, where it is initially processed for speech, sounds, or music, without transcribing or storing the raw audio. This buffer is a continuously overwritten stream that exists only within the protected hardware and never creates an audio recording.