## 3 Results
### Recording Distance: 0.6 m  
The results of the ACC for all speakers at a recording distance of 0.6 m are shown in Figure 4; their median values under noises are reported in Table 2. For the recording distance of 0.6 m, no significant effects of wearing a mask with no noise on ASR were found for any speakers (\(p>0.276\)). The medians of ACC with no noise were 100% for all mask conditions. Under restaurant noise, mask-wearing significantly affected ASRD (H = 18.599, \(p\) = 0.005) and ASRT (H = 12.694, \(p\) = 0.048). For ASRD, the ACCs under restaurant noise for mask conditions compared to than that in the M0 condition were as follows: for the M1 condition it was 19.3 pp less (H = 70.910, \(p\) = 0.013), for the M2 condition it was 21.4 pp less \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**ASR\({}_{\text{D}}\)**} & \multicolumn{2}{c}{**ASR\({}_{\text{T}}\)**} \\ \cline{2-5}
**Mask Condition** & **Restaurant Noise** & **Speech-Shaped Noise** & **Restaurant Noise** & **Speech-Shaped Noise** \\ \hline M0 & 80.63 & 66.67 & 92.58 & 88.56 \\ \hline M1 & 76.92 & 60.00 & 93.33 & 81.80 \\ \hline M2 & 72.47 & 58.96 & 91.67 & 80.48 \\ \hline M3 & 86.19 & 59.55 & 93.54 & 81.82 \\ \hline M4 & 75.96 & 61.32 & 87.08 & 72.73 \\ \hline M5 & 77.35 & 66.67 & 96.88 & 80.63 \\ \hline M6 & 84.41 & 70.59 & 88.89 & 84.62 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Median ACC (%) for all speakers under noises at a recording distance of 0.2 m.  
Figure 3: The word accuracy (ACC) values for all speakers at a recording distance of 0.2 m. (**a**) ASRD, no noise; (**b**) ASRT, no noise; (**c**) ASRD, restaurant noise; (**d**) ASRT, restaurant noise; (**e**) ASRD, speech-shaped noise; and (**f**) ASRT, speech-shaped noise. (H = 87.910, \(p\) = 0.002), for the M3 condition it was 14.3 pp less (H = 59.400, \(p\) = 0.037), and for the M4 condition it was 14.8 pp less (H = 73.290, \(p\) = 0.010). Despite the lack of significance, the ACC of ASR\({}_{\rm D}\) under restaurant noise in the M5 condition was 11.3 pp less than that in the M0 condition (H = 26.135, \(p\) = 0.358). For ASR\({}_{\rm T}\), the ACC under restaurant noise in the M2 condition was 9.3 pp less than that in the M0 condition (H = 78.270, \(p\) = 0.005), and for the M4 condition it was 8.0 pp less than that for M0 (H = 71.790, \(p\) = 0.010). Despite the lack of significance, the ACC of ASR\({}_{\rm T}\) under restaurant noise in the M5 condition was 8.0 pp less than that in the M0 condition (H = 43.015, \(p\) = 0.123). Under speech-shaped noise, mask-wearing had significant main effects on ASR\({}_{\rm T}\) (H = 32.092, \(p\) < 0.001), whereas no significant main effects of wearing a mask on ASR\({}_{\rm D}\) were found (H = 12.483, \(p\) = 0.052). Despite the lack of significance, the ACC of ASR\({}_{\rm D}\) under speech-shaped noise in the M1 condition was 8.7 pp less than that in the M0 condition, in the M2 condition it was 12.5 pp less than that for M0, and in the M4 condition it was 13.5 pp less than that for M0. For ASR\({}_{\rm T}\), the ACC under speech-shaped noise in the M2 condition was 30.9 pp less than that in the M0 condition (H = 118.290, \(p\) < 0.001), in the M3 condition it was 14.2 pp less than that for M0 (H = 81.760, \(p\) = 0.004), in the M4 condition it was 17.3 pp less than that for M0 (H = 86.655, \(p\) = 0.002), and in the M5 condition it was 19.6 pp less than that for M0 (H = 83.565, \(p\) = 0.003). Figure 4: The ACC for all speakers at a recording distance of 0.6 m. (**a**) ASR\({}_{\rm D}\), no noise; (**b**) ASR\({}_{\rm T}\), no noise; (**c**) ASR\({}_{\rm D}\), restaurant noise; (**d**) ASR\({}_{\rm T}\), restaurant noise; (**e**) ASR\({}_{\rm D}\), speech-shaped noise; and (**f**) ASR\({}_{\rm T}\), speech-shaped noise. Kruskal–Wallis tests and post-pairwise comparisons: *, \(p\) < 0.05; ***, \(p\) < 0.01; and ***, \(p\) < 0.001.