## 3 Results  
### Postural Balance Performance Without Cognitive Tasks  
The three-way ANOVA demonstrated significant main effects for Sound, Vision, and Surface, with only interactions for (Sound \(\times\) Surface) (Table 1). On the firm surface in the OE condition, no significant differences in CoP\({}_{\rm{Vm}}\) values were observed among all Sound conditions. However, during the CE condition on the firm surface, CoP\({}_{\rm{Vm}}\) values decreased with nature sounds compared to no sound (\(p\) = 0.013) and noise sound (\(p\) = 0.002), with no significant difference between noise sound and no sound conditions (Figure 2). On the foam surface in the OE condition, no significant differences in CoP\({}_{\rm{Vm}}\) values were found between no sound and nature sound and between no sound and noise sound. A significant increase in CoP\({}_{\rm{Vm}}\) values in the noise sound condition compared to nature sound was observed (\(p\) = 0.016) (Figure 2). Under the CE condition on the foam surface, there were no significant differences in CoP\({}_{\rm{Vm}}\) values between no sound and nature sound conditions. However, a significant increase in CoP\({}_{\rm{Vm}}\) values in the noise sound condition compared to no sound (\(p\) = 0.020) and nature sound (\(p\) < 0.001) conditions (Figure 2). The transition from OE to CE led to a significant increase in CoP\({}_{\rm{Vm}}\) values across sound conditions on both firm and foam surfaces (\(p\) < 0.005), except for the nature sound condition on the firm surface (\(p\) = 0.055) (Figure 2). Shifting from a firm to a foam surface resulted in a significant increase in CoP\({}_{\rm{Vm}}\) values across all conditions (\(p\) < 0.001) (Figure 2).  
\begin{table}
\begin{tabular}{c c c c} \hline CoPV\({}_{\text{vm}}\) values while counting task & & & \\ \hline Sound & 11.82 & =0.001 & 0.58 \\ Vision & 136.49 & \textless{}0.001 & 0.88 \\ Surface & 204.60 & \textless{}0.001 & 0.91 \\ Sound \(\times\) Vision & 0.71 & =0.50 & - \\ Sound \(\times\) Surface & 4.80 & =0.02 & 0.36 \\ Vision \(\times\) Surface & 18.08 & \textless{}0.001 & 0.50 \\ Sound \(\times\) Vision \(\times\) Surface & 0.02 & =0.90 & - \\ \hline CoPV\({}_{\text{vm}}\) values while verbal fluency task & & & \\ \hline Sound & 10.62 & =0.001 & 0.55 \\ Vision & 116.76 & \textless{}0.001 & 0.86 \\ Surface & 209.18 & \textless{}0.001 & 0.92 \\ Sound \(\times\) Vision & 1.12 & =0.34 & - \\ Sound \(\times\) Surface & 6.07 & =0.01 & 0.41 \\ Vision \(\times\) Surface & 15.16 & =0.001 & 0.45 \\ Sound \(\times\) Vision \(\times\) Surface & 1.02 & =0.37 & - \\ \hline Counting performance (number of errors) while & & & \\ postural balance task & & & \\ \hline Sound & 56.76 & \textless{}0.001 & 0.87 \\ Vision & 19.03 & \textless{}0.001 & 0.51 \\ Surface & 1.99 & =0.17 & - \\ Sound \(\times\) Vision & 2.03 & =0.16 & - \\ Sound \(\times\) Surface & 0.35 & =0.71 & - \\ Vision \(\times\) Surface & 0.10 & =0.91 & - \\ Sound \(\times\) Vision \(\times\) Surface & 0.40 & =0.67 & - \\ \hline Verbal fluency (correct number) while postural & & & \\ balance task & & & \\ \hline Sound & 162.12 & \textless{}0.001 & 0.91 \\ Vision & 30.29 & \textless{}0.001 & 0.62 \\ Surface & 12.48 & =0.002 & 0.40 \\ Sound \(\times\) Vision & 2.40 & =0.12 & - \\ Sound \(\times\) Surface & 2.51 & =0.11 & - \\ Vision \(\times\) Surface & 0.41 & =0.52 & - \\ Sound \(\times\) Vision \(\times\) Surface & 0.85 & =0.44 & - \\ \hline \end{tabular}
\end{table}
Table 1: _Cont._  
Figure 2: Center of pressure values mean velocity (CoPV\({}_{\text{vm}}\)) in firm and foam surfaces under open eye (OE) and closed eye (CE) under no sound, nature sound, and noise sound. **: Significant difference (\(p<0.01\)) between no sound and nature sound and between no sound and noise sound. **: Significant difference (\(p<0.05\), \(p<0.01\)) between nature sound and noise sound. **: Significant difference (\(p<0.001\)) between OE and CE conditions. _EEE_: Significant difference (\(p<0.001\)) between firm and foam surfaces.