## 3 Results  
All the participants involved in this study were males. The ages ranged from 26 to 56, while the working durations ranged from 1 year to 35 years. There was no significant difference between the groups regarding age, working duration, education level, and perceived hearing status. The characteristics of workers involved in this study are summarised in Table 2.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Variables** & **Control (\(n=30\))** & **Intervention (\(n=30\))** & \(p\)**-Value** \\ \hline Age (years) & 41.43 (8.67) a & 40.2 (10.26) a & 0.617 b \\
21–30 & 6 & 7 & 0.053 c \\
31–40 & 7 & 10 & \\
41–50 & 12 & 3 & \\
51–60 & 5 & 10 & \\ Working duration (years) & 16.07 (9.32) a & 14.87 (10.94) a & 0.649 b \\
1–10 & 9 & 11 & 0.349 d \\
11–20 & 9 & 9 & \\
21–30 & 11 & 6 & \\
31–40 & 1 & 4 & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Sociodemographic characteristics and perceived hearing status of study participants.  
The workers' self-reported HPD use and intention to use HPD are shown in Table 3. Paired \(t\)-tests were performed to analyse the values recorded at two time points: baseline and follow-up. There were significant improvements in HPD use and the intention to use HPD for workers who received the targeted intervention. As for the control group, the changes were not found to be significant.  
Repeated-measures ANOVA was performed to determine the effect of time and training type on HPD use and intention to use HPD, as shown in Table 4. There was an overall significant change in the HPD use over time, and a significant interaction between training type and time. As for the intention to use HPD, there was an overall significant change over time, but there was no significant interaction between training type and time. The changes in HPD use and the intention to use HPD for both groups are visualised in Figure 2.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Measures** & **ANOVA** & **F (df)** & **np2** & **_p-Value_** \\ \hline \multicolumn{5}{c}{HPD use} \\ Time a  & 7.14 (1.9, 110.4) & 0.11 & 0.001 c  \\ Training type b  & 1.456 (1, 58) & 0.024 & 0.232 \\ Time x Training type & 4.091 (1.9, 110.4) & 0.066 & 0.021 c  \\ Time a  & 4.668 (2, 116) & 0.074 & 0.011 \\ Training type b  & 0.011 & 0.882 \\ Time x Training type & 1.622 (2, 116) & 0.027 & 0.202 \\ \hline \hline \end{tabular} Note. ANOVA = Analysis of variance; a Baseline, post-training, & follow-up; b Control & targeted intervention; c Huynh-Feldt correction was applied.  
\end{table}
Table 4: Changes in HPD use and intention to use HPD according to training types—Repeated Measures ANOVA.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Variables** & **Control (_n = 30_)** & **Intervention (_n = 30_)** & _p-Value_ \\ \hline Education level & & & \\ Primary school & 2 & 2 & 1d  \\ Secondary school & 25 & 26 & \\ College/University & 3 & 2 & \\ Perceived hearing status & & & \\ Poor & 9 & 5 & 0.494 d  \\ Fair & 8 & 10 & 10 \\ Good & 12 & 12 & \\ Excellent & 1 & 3 & \\ \hline \hline \end{tabular}
\end{table}
Table 2: _Cont._  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Measures** & \multicolumn{2}{c}{**Mean (SD)**} & \multicolumn{2}{c}{**Paired Analysis**} \\ \cline{2-5}  & **Baseline** & **Post-Training** & **Follow-Up** & _p-Value_ \\ \hline HPD use & & & & \\ Intervention group & 60.67 (25.63) & 70.50 (25.81) & 77.00 (25.13) & \textless{}0.001 \\ Control group & 58.44 (22.40) & 70.33 (19.21) & 60.55 (27.62) & 0.675 \\ Intention to use HPD & & & \\ Intervention group & 77.33 (23.18) & 82.33 (22.39) & 89.33 (15.3) & 0.004 \\ Control group & 78.0 (12.43) & 86.33 (16.91) & 83.0 (23.8) & 0.247 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Self-reported HPD use and intention to use HPD according to training groups.