发表机构
Universitat Autònoma de Barcelona（巴塞罗那自治大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究量化四类音乐源分离模型对节奏关键信号特性的影响，发现SDR无法反映起音外的节奏特性，模型选择和输入长度会影响节奏相关信号，需在节奏研究中明确报告这些变量。
AI 中文摘要
音乐源分离（MSS）越来越多地用于音乐测量而非混音：分离出的鼓声部为微时序、动态和 groove（律动）研究提供数据。该领域几乎仅通过信号失真比（SDR）评估分离模型，但微节奏研究表明，声音的感知时间位置（即其p中心）由其起音和包络共同决定，而这正是SDR未设计要保护的特性。我们使用包含50首曲目的MUSDB18-HQ测试集，量化涵盖四个架构代际的四个开源分离模型（Spleeter、HT-Demucs、BS-Roformer、SCNetXL）对节奏关键信号特性的影响，其中真实声部可验证所有结论。得出三项发现：（1）起音时间是稳定的：起音F值与SI-SDR的斯皮尔曼相关系数为0.62，且与输入长度无关；（2）瞬态和动态特性并非稳定：其失真与SI-SDR的相关性极弱（|ρ|≤0.29），且模型排名反转——SDR领先模型对鼓起音的失真程度是与其性能匹配的卷积神经网络（CNN）对应模型的两倍，而SDR最差模型对动态特性的保留优于中等水平模型；每个模型都会对动态轮廓施加系统性的、模型特有的偏差；（3）输入长度会改变固定段落的呈现起音（对Transformer模型的影响略大，配对p值为0.044），但不改变起音位置。对于节奏研究，分离模型的选择和输入条件是需报告的方法论变量，仅靠SDR无法替代这些变量。
英文摘要
Music source separation (MSS) is increasingly used not to remix music but to measure it: separated drum stems feed studies of microtiming, dynamics, and groove. The field evaluates separators almost exclusively by signal-to-distortion ratio (SDR), yet microrhythm research shows that a sound's perceived temporal location (its p-centre) is co-determined by its attack and envelope, precisely the properties SDR was not designed to protect. We quantify what four open separators spanning four architecture generations (Spleeter, HT-Demucs, BS-Roformer, SCNetXL) do to rhythm-critical signal properties, using the 50-track MUSDB18-HQ test set, where true stems make every claim falsifiable. Three findings emerge. (1) Onset timing is safe: onset F-measure tracks SI-SDR (Spearman rho = 0.62) and is invariant to input length. (2) Transient and dynamic shape are not: their distortion correlates only weakly with SI-SDR (|rho| <= 0.29), and the model ranking inverts - the SDR leader distorts drum attacks twice as much as its capability-matched CNN counterpart, while the SDR-worst model preserves dynamics better than a mid-pack one. Each model imposes a systematic, model-specific bias on the dynamic profile. (3) Input length reshapes the rendered attack of a fixed passage (marginally more for the transformer; paired p = 0.044) while leaving onset locations untouched. For rhythmic studies, separator choice and input conditions are methodological variables to be reported, and SDR alone cannot stand in for them.
Comments11 pages, 2 figures
