## 5 Results and Discussion
### Pearson Correlation Coefficient and p-Value  
The Pearson correlation coefficient, often denoted as '\(r\)', is used to measure the strength and direction of the linear relationship between two variables. The value of this coefficient lies between \(-1\) and \(1\), indicating the strength and direction of the linear relationship between the variables. Closer to 1: Indicates a strong positive linear relationship between the variables. As one variable increases, the other variable increases proportionally. Closer to \(-1\): Indicates a strong negative linear relationship between the variables. As one variable increases, the other variable decreases proportionally. Closer to 0: Indicates no linear relationship between the variables [(1998)]. The Pearson correlation coefficient is calculated using the following formula. \[r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{\left[n\sum x^{2}-(\sum x)^{2} \right]\left[n\sum y^{2}-(\sum y^{2})\right]}} \tag{1}\]  
where  
\(n\) is the number of data points. \(\sum xy\) is the sum of the products of the two variables. \(\sum x\) and \(\sum y\) are the sum of the first and second variables, respectively. \(\sum x^{2}\) and \(\sum y^{2}\) are the sum of the squares of the first and second variables, respectively. \begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline
**Category** & \begin{tabular}{c} **Not** \\ **at All** \\ \end{tabular} & \begin{tabular}{c} **Barely** \\ **Not** \\ \end{tabular} & \begin{tabular}{c} **Slightly Not** \\ **So** \\ \end{tabular} & \begin{tabular}{c} **Moderately** \\ **So** \\ \end{tabular} & \
\begin{tabular}{c} **Somewhat So** \\ \end{tabular} &
\begin{tabular}{c} **Slightly** \\ **So** \\ \end{tabular} \\ \hline
1. Noise onboard affects sleep, stress, and work performance & 7.7 & 5.1 & 7.6 & 16.3 & 27.1 & 24.4 & 11.8 \\ \hline
2. Falling sheep takes a long time due to the noise onboard the ship & 14.0 & 22.6 & 8.1 & 22.2 & 22.6 & 6.3 & 4.1 \\ \hline
3. Often woken up by the noise onboard the ship during the voyage & 20.8 & 23.1 & 10.0 & 19.5 & 17.2 & 6.3 & 3.2 \\
4. Difficult to fall back sleep due to the noise inside the ship while on board & 20.8 & 25.8 & 10.9 & 18.6 & 16.7 & 5.0 & 2.3 \\
5. Frequently tossing and turning due to the noise inside the ship while on board & 16.7 & 25.8 & 8.6 & 22.6 & 14.9 & 9.0 & 2.3 \\ \hline
6. Difficulty sleeping soundly due to onboard noise while on the ship & 16.3 & 21.7 & 10.4 & 21.3 & 17.2 & 9.5 & 3.6 \\
7. Many issues arise from sleep disturbances while on board the ship & 16.7 & 25.3 & 11.3 & 19.9 & 14.0 & 8.6 & 4.1 \\
8. Worried about not being able to sleep well while on board & 18.1 & 16.3 & 8.1 & 19.9 & 15.8 & 13.1 & 8.6 \\ \hline
9. Straggling to sleep at night due to the noise inside the ship while on board & 17.6 & 24.0 & 7.7 & 22.6 & 16.3 & 7.2 & 4.5 \\ \hline
10. Difficulty sleeping due to noise inside the ship when the main engine is shut & 21.3 & 26.2 & 11.3 & 21.3 & 12.7 & 4.5 & 2.7 \\ down during anachorage at or not & & & & & & & \\ \hline
11. Difficulty sleeping due to onboard noise while the main engine is running & 18.6 & 25.3 & 8.1 & 26.2 & 12.7 & 7.2 & 1.8 \\ during navigation & & & & & & & \\ \hline
12. Feehring very tired upon waking up in the morning while on board & 2.7 & 3.6 & 4.1 & 16.3 & 30.3 & 25.3 & 17.6 \\
13. Not getting enough sleep at night while on board & 5.4 & 9.0 & 5.0 & 22.2 & 25.8 & 23.1 & 9.5 \\ \hline
14. Immediately getting up upon waking while on board & 6.8 & 15.4 & 14.9 & 21.3 & 12.2 & 20.8 & 8.6 \\ \hline
15. Feeling slepy throughout the daytime while on board & 0.9 & 5.4 & 4.5 & 20.4 & 28.1 & 28.1 & 12.7 \\ \hline
16. Indadequate sleep while on board affects daily life & 2.3 & 4.5 & 2.7 & 19.0 & 24.4 & 30.3 & 16.7 \\ \hline
17. Often taking naps during the day while on board & 19.9 & 18.1 & 10.9 & 20.4 & 16.7 & 10.9 & 3.2 \\ \hline
18. Unable to sleep well due to onboard noise while sleeping on the ship & 20.4 & 24.4 & 10.4 & 21.7 & 16.3 & 5.0 & 1.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Impact of noise on sleep and fatigue.