## 4 Experimental Verification  
In the experimental part, the proposed method was applied to the signals from the marine animals False Killer Whale, Baird's Beaked Whale, Weddell Seal, and Bottlenose Dolphin [38]. As marine animals use sound for echolocation and communication, it is very important to analyze these sound signals in studying the behavior of marine animals. As shown in Figure 8, the time-domain diagram of the animal sound signal and the time-frequency diagram processed by the ACMD method are shown, where \(\alpha=1\times 10^{-3},\beta=1\times 10^{-4}\). It can be observed from the time-frequency diagram that there is noise interference in the signal. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \(a\) & \(\beta\) & \(2.9\times 10^{-4}\) & \(2.9\times 10^{-4}\) &  
Figure 8: Four kinds of animal sound signals and the time-domain diagram processed by ACMD method (**(a)**. The time-domain diagram of the False Killer Whale sound signal and the time–frequency diagram processed by the ACMD method a, where \(\alpha=1\times 10^{-3}\), \(\beta\)= \(1\times 10^{-4}\); **(b)**. The time-domain diagram of the Baird’s Beaked Whale sound signal and the time–frequency diagram processed by the ACMD method a, where \(\alpha=1\times 10^{-3}\), \(\beta\)= \(1\times 10^{-4}\); **(c)**. The time-domain diagram of the Weddell Seal sound signal and the time–frequency diagram processed by the ACMD method a, where \(\alpha=1\times 10^{-3}\), \(\beta\)= \(1\times 10^{-4}\); **(d)**. The time-domain diagram of the Bottlenose Dolphin sound signal and the time–frequency diagram processed by the ACMD method a, where \(\alpha=1\times 10^{-3}\), \(\beta\)= \(1\times 10^{-4}\)). The method proposed in this article is employed to find the optimal \(\alpha,\beta\) value, and its optimization result is shown in Figure 9. Due to a large amount of data, this article will locally enlarge around its maximum point of SNR. The \(\alpha,\beta\) corresponding to the maximum point of the four types of biological SNR in the Figure 10 is: False Killer Whale, \(\alpha=3.26\times 10^{-3},\beta{=1\times 10^{-6}}\); Baird's Beaked Whale, \(\alpha=9.96\times 10^{-3}\), \(\beta{=9.96\times 10^{-4}}\); Weddell Seal, \(\alpha=9.96\times 10^{-3}\), \(\beta{=9.96\times 10^{-4}}\); Bottlenose Dolphin, \(\alpha=9.86\times 10^{-3}\),\(\beta{=9.76\times 10^{-4}}\). The most suitable \(\alpha,\beta\) is brought into ACMD and the marine animals' signal is processed to obtain the results shown in Figure 10. Compared to the time-frequency diagram in Figures 8 and 10, it can be observed that the signal noise in Figure 10 is less, which proves the effectiveness of the method proposed in this paper. In order to describe the change in the SNR before and after improvement, this paper uses Equation (17) to show the change in the SNR before and after. According to Equation (17), the SNRs of the False Killer Whale, Baird's Beaked Whale, Weddell Seal, and Bottlenose Dolphin that increased are 672.018%, \(-\)185.595%, 7.777%, and 32.759%, respectively. Table 4 lists the SNR changes before and after ACMD optimization. Although the improvement in [PERSON]'s beaked whale is \(-\)185.595%; in fact, the SNR is increased from \(-\)2.443 to \(-\)1.434. In Tables 5-8, 100 SNR parameters around the maximum SNR of four marine animals are listed. Figure 9: The most suitable \(\alpha\) and \(\beta\) for four kinds of animals (**(a)**. False Killer Whale’s locally enlarge around maximum point of SNR; **(b)**. [PERSON]’s Beaked Whale’s locally enlarge around maximum point of SNR; **(c)** Weddell Seal’s locally enlarge around maximum point of SNR; **(d)** Bottlenose Dolphin’s locally enlarge around maximum point of SNR).