## 1 Introduction
[18] revealed that waves scour soil particles as they climb the slope, eventually leading to wave erosion niches and collapses. The erosion rate initially peaks then decays exponentially. Many scholars have studied the characteristics of slope failure through seismic signals. [PERSON] et al. [19] identified three types of riverbank landslides through model tests and found that the characteristics and processes of these landslides correspond to their seismic signals and time-frequency spectra. The three types of riverbank landslides are as follows. (a) Single landslide: Soil slides along the same sliding surface. (b) Intermittent landslide: Soil gradually slides intermittently along the same sliding surface. (c) Successive landslide: Different soils continuously slide from different sliding surfaces. [PERSON] et al. [20] conducted model tests simulating landslides due to seepage and identified precursor signals from single landslide-induced seismic signals, which are helpful for landslide early warning. [PERSON] et al. [21] recorded seismic signals of a slope model in a field test, showing that seismic signals of landslide events can be recognized even when the slope model is eroded by floods. [PERSON] et al. [22] explained the main physical processes of rock slope failure through seismic signals. Their research showed that rock slope failure events mainly include multiple mass slides, toppling, and interactions of rock mass. Multiple rocksslides present pulse-like characteristics in the time-frequency spectrum, reflecting the sudden, brief seismic peaks generated each time rocks hit the ground. Boulders impacting show columnar features in the time-frequency spectrum, indicating a period of intense vibration. Slope sliding and rock collisions produce different seismic time-frequency spectrum traces, which help to distinguish different landslide events. [PERSON] and [PERSON] [23] analyzed the seismic signals of rockfall events of different sizes. Their findings indicatedthat smaller rockfall events, involving less rock mass or covering smaller areas, produced seismic signals mainly concentrated at higher frequencies; larger rockfall events, involving more massive rocks or covering more extensive areas, produced stronger low-frequency responses. This demonstrates that different collapse behaviors produce distinct collapse intensities and delays. By monitoring seismic signals, we can track these events. The impact of wave erosion on slope stability, particularly through changes in pore pressure, has been a significant focus of research across various studies. [PERSON] et al. [24] explored how water level changes and wave erosion affect slope stability, noting the roles of seepage, wave swash, and hydraulic gradient in reducing soil strength and potentially leading to slope failure. [PERSON] and [PERSON] [25] studied interactions between swash and groundwater, finding that swashes extending above the mean groundwater level cause a rise in the groundwater table, impacting slope stability. [PERSON] et al. [26] used flume experiments to study the influence of water level and wave height on dam stability, demonstrating the relationship between pore pressure changes and wave activity. Monitoring the acoustic signals of wave erosion and slope failure helps to understand the condition of wave-eroded slopes. Previous research has indicated that seismic signals associated with the movement of materials and acoustic signals are related and complementary. The combination of these two types of sensors can serve as the basis for disaster monitoring and warning systems. However, research on the analysis of acoustic signals from wave-eroded slopes is currently lacking, with most studies focusing on debris flows and rockfall events. Nevertheless, valuable insights and characteristics of acoustic signals can still be gleaned from these studies. [PERSON] et al.