We present LubDubDecoder, a system that enables fine-grained monitoring of micro-cardiac vibrations associated with the opening and closing of heart valves across a range of hearables. Our system transforms the built-in speaker, the only transducer common to all hearables, into an acoustic sensor that captures the coarse "lub-dub" heart sounds, leverages their shared temporal and spectral structure to reconstruct the subtle seismocardiography (SCG) and gyrocardiography (GCG) waveforms, and extract the timing of key micro-cardiac events. In an IRB-approved feasibility study with 25 users, our system achieves correlations of 0.88-0.95 compared to chest-mounted reference measurements in within-user and cross-user evaluations, and generalizes to unseen hearables using a zero-effort adaptation scheme with a correlation of 0.91. Our system is robust across remounting sessions and music playback.

翻译：我们提出LubDubDecoder系统，该系统能够在多种可听设备上实现与心脏瓣膜开闭相关的微小心脏振动的细粒度监测。我们的系统将内置扬声器——所有可听设备共有的唯一换能器——转化为声学传感器，用于捕捉粗糙的"lub-dub"心音；利用其共享的时频结构重建细微的心震图（SCG）与心转动图（GCG）波形；并提取关键微小心脏事件的时间信息。在一项经IRB批准的包含25名用户的可行性研究中，本系统在用户内与跨用户评估中与胸戴式参考测量结果的相关系数达到0.88-0.95，并通过零成本适配方案在未见过的可听设备上实现0.91的相关系数。我们的系统在重新佩戴场景和音乐播放条件下均表现出稳健性。