Unlike the conventional non-Hermitian skin effect (NHSE) that localizes bulk wave functions to the boundary, the hybrid skin-topological effect (HSE) arises from the interplay between topological edge states and the non-Hermitian skin effect, resulting in the further localization of edge state wave functions at the corners of the sample. While the HSE has been observed in passive platforms, these experimental investigations have generally been constrained by inherent material dissipation, often restricting observations to comparison or indirect reconstructions. In such systems, rapid energy dissipation made it difficult to determine whether localization originated from non-Hermitian physical mechanisms or simple energy loss, posing a significant challenge for the direct observation of the non-Hermitian skin states. Here, we introduce the complex-frequency excitation technique into a two-dimensional acoustic coupled-ring network to overcome the loss limits, successfully enabling the direct observation of the spin-dependent transient HSE. Our experiments clearly visualize the dynamic evolution of edge states with distinct pseudospins as they accumulate at opposite corners over time. This work not only establishes a pathway for detecting non-Hermitian eigenstates in lossy systems but also provides a versatile platform for the development of pseudospin-controlled topological acoustic devices.

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• Skin effect
• Topological edge modes
• Topological effects in acoustic systems
• Acoustic metamaterials
• Non-Hermitian systems
• Topological metamaterials
• Spin
• Surface acoustic wave