Background: Infant cry acoustics provide a promising window into early neurodevelopment and may serve as scalable biomarkers for neurodevelopmental disorders. However, conventional microphone-based recordings are highly susceptible to environmental noise and raise privacy concerns in real-world clinical settings. Chest-surface accelerometers may offer a robust alternative by capturing vibrations directly from the larynx. Methods: We evaluated the validity of a chest-mounted accelerometer (ACC) for infant cry analysis by comparing acoustic features derived from ACC and simultaneously recorded microphone (MIC) signals during routine vaccination visits. The final sample included 85 infants (41 at 4 months; 44 at 12 months) from a diverse pediatric population. Seven vocal measures were extracted from both modalities, including fundamental frequency (F0), jitter, shimmer, cepstral peak prominence (CPP), and harmonics-to-noise ratio (HNR). Agreement and consistency between modalities was assessed using intraclass correlation coefficients (ICCs). Results: F0 demonstrated excellent agreement between ACC and MIC recordings (ICC > 0.94). Jitter measures also showed good-to-excellent agreement, while CPP demonstrated moderate agreement. Shimmer and HNR showed lower absolute agreement and systematic bias between modalities, reflecting possible differences in signal transmission and noise sensitivity. Conclusion: In summary, chest-surface accelerometers can reliably capture several clinically relevant acoustic features of infant cry, particularly temporal measures of F0 and jitter. This approach offers a noise-robust and privacy-preserving alternative to microphone-based recordings, supporting its potential use in scalable clinical and developmental research applications.

翻译：背景：婴儿哭声声学特征为早期神经发育提供了重要窗口，并可能成为神经发育障碍的可扩展生物标记物。然而，传统基于麦克风的录音极易受环境噪声干扰，且在实际临床场景中存在隐私问题。胸部表面加速度计通过直接捕捉喉部振动，可能提供一种稳健的替代方案。方法：我们通过比较常规疫苗接种期间，从胸部加速度计（ACC）与同步记录的麦克风（MIC）信号中提取的声学特征，验证了胸部加速度计在婴儿哭声分析中的有效性。最终样本包含85名婴儿（4月龄41名；12月龄44名），来自多元化儿科人群。从两种模态中提取了七项声学指标，包括基频（F0）、抖动、闪变、倒谱峰值突出度（CPP）以及谐噪比（HNR）。采用组内相关系数（ICC）评估模态间的一致性与稳定性。结果：F0在ACC与MIC记录间呈现极佳一致性（ICC > 0.94）。抖动指标亦显示良好至极佳一致性，而CPP表现为中等一致性。闪变与HNR的绝对一致性与模态间系统偏差较低，可能反映了信号传输与噪声敏感性的差异。结论：综上，胸部表面加速度计可可靠地捕获婴儿哭声的多项临床相关声学特征，特别是F0与抖动的时域指标。该方法为基于麦克风的录音提供了抗噪且保护隐私的替代方案，支持其在可扩展的临床与发育研究中的应用潜力。