Apple Watch Series 12 Hands-On: A New Sensing System and Audio Intelligence Suite

At its recent “Surprise and shine” keynote, Apple unveiled the Series 12 of its signature smartwatch, delivering a roster of updates that exceeded initial expectations. While some enhancements, such as Readiness scores and higher sampling rates, align with competitor offerings, the Series 12 introduces novel capabilities centered around a re-architected health sensing system and a new suite of audio intelligence features.

The most visible hardware change resides on the watch’s underside. Unlike the four LEDs arranged in a diamond pattern on the Series 11, the new model features a ring of 12 lights. Apple reports that this redesign, along with adjustments to photodiodes and electrodes, increases the surface area in contact with the skin. This hardware overhaul, combined with elevated sampling rates for heart rate, VO2Max, and heart rate variability (HRV), aims to deliver more precise and consistent biometric readings. The company claims its own comparative study identified the Series 12 as the market leader in heart rate sensing accuracy.

These sensing improvements feed into updated health applications. The new Readiness app provides a daily score from 0 to 10, incorporating activity, sleep quality, and vitals. Additionally, HRV is now measured up to every five minutes, a significant increase from the two-to-four-hour intervals of previous generations. The Vitals app has also been refined with new performance language, and a revamped Health app—available later this year—will utilize Apple Intelligence to provide time-sensitive summaries and reorganized metric tiles. A new Longevity tab will introduce a “health age” metric alongside assessments for areas like VO2Max.

Beyond health, the Series 12 introduces “Audio Intelligence” tools powered by the S11 chip’s secure exclave, where raw audio is processed locally. Key features include an enhanced Shazam function that can identify songs played within the last 15 seconds almost instantly, and sound recognition alerts for critical noises like alarms or sirens, even when the paired iPhone is not nearby.

Perhaps the most notable additions are Live Rewind and Siri Recap. Live Rewind allows users to double-click the digital crown to view a transcript of the previous 15 seconds of nearby conversation. Siri Recap generates high-level summaries of events, such as meetings, rather than full transcripts. Apple emphasizes that no audio is stored; the system uses a rolling buffer that overwrites itself, ensuring privacy. While Siri Recap transfers encrypted data to the iPhone for processing, Apple states these files remain inaccessible to the OS, apps, or users.

The Series 12 also debuts a new ceramic variant, praised for its smooth, porcelain-like finish. Detailed performance and battery life evaluations will be available in a full review once testing units are released.