## 5 Conclusions  
This study uses an experimental- and simulation-based approach to examine the influence of foam acoustic parameters on the sound radiation capability of reinforced sandwich panels filled with foam within the 1-2000 Hz frequency range. The following findings are reported:  
1. Without taking into account structural effects, modifying the acoustic parameters of foam has a minor influence on the peak frequency of radiated sound power, as well as the sound radiation performance in non-peak frequency ranges of the sandwich panel. Nevertheless, it has a significant impact on the peak radiated sound power.
2. Within a reasonable range of foam parameter values, the porosity has a minimal impact on sound radiation performance; hence, it can be practically ignored. Peak sound radiation performance is significantly affected by static flow resistivity and tortuosity factors. A 20% variance in static flow resistivity and a 100% variance in tortuosity factor resulted in a decrease of 1.44 dB and 2.91 dB, respectively, in the peak radiated sound power level at specific frequencies. Technical term abbreviations such as \"static flow resistivity\" and \"tortuosity factor\" will be explained upon first use.
3. Among the other foam parameters, reducing the thermal characteristic length and raising static flow resistivity both improve the plate's sound radiation performance. Nevertheless, the effects of the tortuosity factor and viscous characteristic length on the sound radiation vary depending on the frequency. Specifically, within the 1-1000 Hz frequency range, reducing the tortuosity factor and lengthening the viscous characteristic both enhance the plate's sound radiation efficiency. In contrast, within the 1000-2000 Hz frequency range, the converse trend is apparent.  
This study has practical applications in real-life contexts. For example, in residential, commercial, and industrial construction domains, our research findings provide guidance to architects and engineers on how to optimize sandwich panel materials to achieve superior sound insulation. This creates a calmer indoor environment [24]. In the field of aerospace engineering, aircraft manufacturers can achieve effective noise reduction for passengers during flights by adjusting the foam parameters in sandwich panels. This results in a more comfortable flying experience. These application cases demonstrate the practical application of our research, offering guidance across a range of domains. They highlight the importance of our research in improving environmental quality, enhancing product performance, and providing superior user experiences [25; 26].  
[PERSON], proposed the ideas, steps, and details of the experiment, most of the experiments were completed by [PERSON], [PERSON], [PERSON], W.K. and L.W., where [PERSON] was instrumental in the proper conduct of the experiments and wrote the article together with [PERSON], and all the authors analyzed the data and discussed the conclusions. All authors have read and agreed to the published version of the manuscript.  
The work is supported by the 2022 Knowledge Innovation Dawn Special Plan Project (202201080102039), Research and Innovation Initiatives of WHPU (2022)04, Natural Science Foundation of Hubei Province (2021 CFB292). This work was finished at Wuhan Polytechnic University, Wuhan.  
Not applicable for studies not involving humans or animals.