## 4 Experiments and Discussion
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Patient** & **Method** & **Domain** & **Embedding Parameters** & **Amplitude Similarity** & **SNR** \\ \hline \multirow{8}{*}{9} & \multirow{4}{*}{Reference [9]} & \multirow{4}{*}{Time domain} & \(Q=500\) & 0.99 & 35.26 \\  & & & \(Q=2000\) & 0.99 & 34.53 \\  & & & \(Q=5000\) & 0.97 & 34.25 \\  & & & \(Q=5000\) & 1 & 40.23 \\  & & & \(Q=2000\) & 1 & 32.71 \\  & & & \(Q=5000\) & 0.99 & 25.14 \\  & & & \(Q=5000\) & 1 & 39.49 \\  & & & \(Q=2000\) & 0.99 & 39.12 \\  & & & \(Q=5000\) & 0.99 & 28.57 \\  & & & \(Q=500\) & 0.99 & 29.67 \\  & & & & \(Q=2000\) & 0.99 & 23.54 \\  & & & \(Q=5000\) & 0.98 & 15.28 \\  & & & \(\varepsilon=2000\), \(n=2\) & 1 & 27.38 \\  & & & (Level 5) & \(\varepsilon=3000\), \(n=3\) & 1 & 26.93 \\  & & & \(\varepsilon=4000\), \(n=4\) & 1 & 26.65 \\ \hline \multirow{8}{*}{10} & \multirow{4}{*}{Reference [9]} & \multirow{4}{*}{Time domain} & \(Q=500\) & 1 & 29.46 \\  & & & \(Q=2000\) & 0.99 & 28.75 \\  & & & \(Q=5000\) & 0.98 & 28.32 \\  & & & \(Q=5000\) & 1 & 31.39 \\  & & & \(Q=2000\) & 1 & 30.21 \\  & & & \(Q=5000\) & 0.96 & 22.17 \\  & & & \(Q=5000\) & 0.97 & 22.75 \\  & & & \(Q=5000\) & 0.99 & 30.71 \\  & & & \(Q=2000\) & 0.96 & 22.34 \\  & & & \(Q=5000\) & 0.94 & 16.89 \\  & & & \(\varepsilon=2000\), \(n=2\) & 1 & 29.83 \\  & & & \(\varepsilon=3000\), \(n=3\) & 1 & 29.39 \\  & & & \(\varepsilon=4000\), \(n=4\) & 0.99 & 29.56 \\ \hline \multirow{8}{*}{11} & \multirow{4}{*}{Reference [23]} & \multirow{4}{*}{Time domain} & \(Q=500\) & 0.98 & 27.96 \\  & & & \(Q=2000\) & 0.97 & 27.53 \\  & & & \(Q=5000\) & 0.96 & 27.43 \\  & & & \(Q=5000\) & 1 & 37.69 \\  & & & \(Q=2000\) & 1 & 32.51 \\  & & & \(Q=5000\) & 0.98 & 21.67 \\  & & & \(Q=5000\) & 1 & 38.19 \\  & & & \(Q=2000\) & 1 & 33.15 \\  & & & \(Q=5000\) & 0.99 & 22.75 \\  & & & \(Q=5000\) & 0.99 & 22.75 \\  & & & \(Q=5000\) & 0.99 & 25.34 \\  & & & \(Q=5000\) & 0.98 & 19.68 \\  & & & \(\varepsilon=2000\), \(n=2\) & 1 & 28.63 \\  & & & \(\varepsilon=3000\), \(n=3\) & 1 & 27.59 \\  & & & \(\varepsilon=4000\), \(n=4\) & 1 & 26.96 \\ \hline \multirow{8}{*}{12} & \multirow{4}{*}{Reference [9]} & \multirow{4}{*}{Time domain} & \(Q=500\) & 0.98 & 27.36 \\  & & & \(Q=2000\) & 0.98 & 28.14 \\  & & & \(Q=5000\) & 0.99 & 27.53 \\  & & & \(Q=5000\) & 1 & 36.49 \\  & & & \(Q=2000\) & 0.99 & 30.81 \\  & & & \(Q=5000\) & 0.98 & 26.21 \\  & & & \(Q=5000\) & 1 & 37.16 \\  & & & \(Q=2000\) & 1 & 29.15 \\  & & & \(Q=5000\) & 0.99 & 24.75 \\  & & & \(Q=5000\) & 1 & 31.87 \\  & & & \(Q=2000\) & 0.99 & 24.39 \\  & & & \(Q=5000\) & 0.98 & 17.68 \\  & & & \(\varepsilon=2000\), \(n=2\) & 1 & 28.93 \\  & & & \(\varepsilon=3000\), \(n=3\) & 1 & 28.49 \\  & & & \(\varepsilon=4000\), \(n=4\) & 0.99 & 28.35 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: \(Cont.\)(1) Low-pass filtering: Low-pass filter is a kind of signal processing so as to give easy passage to low-frequency signals and difficult passage to high-frequency signals. By the BER information in Table 2, one can find that the robustness of the proposed method against the low-pass filter attack with a cutoff frequency of 3000 Hz and 6000 Hz is significantly higher than the methods in [9; 22; 23; 28]. (2) Noise interference: Gaussian noise is a common noise for audio and other signals. Table 3 lists the experimental results of adding Gaussian noise with various noise intensities to the embedded and compressed audio signal. In common noise intensities \(-40\) dB and \(-30\) dB, the robustness of the proposed method is significantly higher than the methods in [9; 22; 23; 28]. (3) Re-sampling: Resampling converts an audio signal from a given sample rate to a different sample rate. Upsampling or interpolation increases the sampling rate, and downsampling or decimation decreases the sampling rate. Both can be accomplished using integer-valued interpolation or decimation factors. In the proposed method, the embedded-compressed audio signal is first decimated from 44,100 Hz to 22,050 Hz and then interpolated to the original 44,100 Hz.