## 1 Introduction
[27] explored the differences between seismic and acoustic signals generated by rocks in riverbeds and indicated that the attenuation rate of acoustic signals in the air is much less than the attenuation rate of seismic signals on the ground. This suggests that acoustic signals can be captured at relatively greater distances, aiding in monitoring over broader areas. Moreover, the data showed that the frequency range of seismic and acoustic signals generated by rock impacts on riverbeds is roughly the same. This frequency similarity indicates that ground seismic signals and airborne acoustic signals originate from the same seismic source, which is crucial for analyzing and interpreting natural phenomena. [PERSON] et al. [28] analyzed the acoustic signals generated by debris flows and found that sound signals can reflect the dynamic characteristics of debris flows. For example, the peak frequency of the signal is related to parameters such as the velocity, depth, and discharge of the debris flow. [PERSON] et al. [29] studied the acoustic signals of debris flows using data from flume experiments and actual monitoring. The research revealed that in the absence of strong external interference, debris flow acoustic signals can be easily distinguished from environmental noise based on their characteristics. For instance, debris flow acoustic signals typically have a very long duration compared to the shorter duration of other noise sources. Acoustic signals, similar to seismic signals, can provide information about the characteristics of material movement and help identify different events through signal features such as duration, amplitude, and spectrum. In general, the breaking and splashing of waves produce sound, and the louder the impact of waves on slopes, the louder the sound may be. Friction between soil particles during slope movement also generates sound. Based on the fact that wave erosion and slope sliding produce acoustic signals with different characteristics, monitoring acoustic signals can help us indirectly infer the intensity of wave impacts or identify coastal slope failure events. The purpose of this study is to investigate the dynamic characteristics of seismic signals, acoustic signals, and pore pressure of slopes under various wave erosion conditions. Therefore, we conducted multiple sets of flume tests involving wave erosion, using waves with varying heights and frequencies to erode the slope models. Seismic and acoustic signals were analyzed using the Hilbert-Huang transform. This study explains the variations in seismic and acoustic signals as well as pore pressure during the test process. We also analyzed the seismic signals generated during slope model sliding and collapses in the tests. Additionally, we conducted a parameter analysis to investigate the influence of wave height and frequency on slope erosion. We obtained some important findings. Wave height plays a more critical role in coastal erosion and retreat than wave frequency; the phenomenon of rapid drawdown, triggered by cyclical swash and backwash, is a key factor inducing slope slides; a shift in erosion mechanisms from swash to direct impact is noted to elevate seismic and acoustic signals, indicating a change in the erosion dynamics. Furthermore, an increase in wave run-up height leads to elevated pore pressure within slope, which is a precursor to intensified erosion. These insights underline the complex interplay between wave dynamics and coastal erosion processes, and can serve as a reference for the implementation of coastal slope monitoring and prewarming.