# An Acoustic Way to Support Japanese Children's Effective English Learning in School Classrooms
## 3 Results and Discussions
### English Test

Table 5: Correct answer rate \(p_{\rm c}\) of each word pair. Special care or perhaps separate training is required when teaching L2 phonemes that do not appear in their L1 phoneme structure. Research showed that mothers often communicate with their infants with a special form of speech, known as \"parentese\", with higher pitch, overemphasised intonation contour, spoken slowly [65]. Additionally, albeit incomplete, many have attempted to develop methods to train Japanese natives (including adults) to learn abilities to differentiate /1/ and /r/, as in [62], for example. Above results suggest sound amplification systems equipped with functions allowing flexible control over realised frequency response could be valuable in second and foreign language education. Finally, to assess the association between the test score and the heterogeneous sound fields in the classroom, we divided the subset with difficulty levels 1-3 words further into four groups according to sound amplification systems (A or B) and seat locations (Front or \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Original C-Statistic** & **Optimism** & **Corrected C-Statistic** \\ \hline Difficulty Level 1–3 & 0.7757 & 0.0006 & 0.7750 \\ Difficulty Level 4 & 0.5931 & 0.0077 & 0.5854 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Bootstrap-validated C-statistic for the multivariate logistic regression models shown in Tables 8 and 9. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Univariate**} & \multicolumn{2}{c}{**Multivariate**} \\ \cline{2-5}  & **OR** & **95\% CI** & **OR** & **95\% CI** \\ \hline Difficulty Level & & & & \\ Level 2 vs. Level 1 & 0.17 *** & (0.15–0.19) & 0.17 *** & (0.15–0.19) \\ Level 3 vs. Level 1 & 0.06 *** & (0.06–0.07) & 0.06 *** & (0.06–0.07) \\ Test Identifier of a lesson & & & & \\
2 nd Test vs. 1 st Test & 0.72 *** & (0.66–0.78) & 0.92 & (0.83–1.01) \\ Week & & & & \\ Week 2 vs. Week 1 & 1.20 *** & (1.10–1.31) & 1.26 *** & (1.14–1.38) \\ Sound Amplification System & & & & \\ System B vs. System A & 1.13 ** & (1.03–1.23) & 1.17 ** & (1.06–1.28) \\ Seat Group & & & & \\ Group 2 vs. Group 1 & 0.90 & (0.78–1.03) & 0.88 & (0.75–1.02) \\ Group 3 vs. Group 1 & 0.93 & (0.80–1.07) & 0.91 & (0.78–1.07) \\ Group 4 vs. Group 1 & 0.81 ** & (0.71–0.92) & 0.77 *** & (0.67–0.90) \\ Group 5 vs. Group 1 & 0.72 *** & (0.63–0.83) & 0.67 *** & (0.58–0.78) \\ \hline \hline (OR = Odds Ratio. Significance codes: *** \(\leq\) 0.001, ** \(\leq\) 0.01). & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Logistic Regression: sub analysis 1 (without Level 4 data). \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Univariate**} & \multicolumn{2}{c}{**Multivariate**} \\ \cline{2-5}  & **OR** & **95\% CI** & **OR** & **95\% CI** \\ \hline Test Identifier of a lesson & & & & \\
2 nd Test vs. 1 st Test & 0.62 *** & (0.46–0.81) & 0.61 *** & (0.46–0.81) \\ Sound Amplification System & & & & \\ System B vs. System A & 0.79 * & (0.63–1.00) & 0.78 * & (0.62–0.99) \\ Seat Group & & & & \\ Group 2 vs. Group 1 & 1.40 & (0.96–2.05) & 1.41 & (0.97–2.06) \\ Group 3 vs. Group 1 & 1.41 & (0.96–2.07) & 1.42 & (0.97–2.08) \\ Group 4 vs. Group 1 & 1.76 ** & (1.23–2.53) & 1.77 ** & (1.23–2.55) \\ Group 5 vs. Group 1 & 1.63 * & (1.12–2.40) & 1.64 * & (1.12–2.41) \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Logistic Regression: sub analysis 2 (Level 4 (the hardest) data only). Back), then compared the medians of test scores (38 questions per system). As shown in Figure 5, the lowest median of the test score is observed in the sub group \"System A at the back seats\", and it is significantly lower than that of \"System B at the back seats\". With System A, the difference between front and back seats is noticed, indicating heterogeneous sound fields in the classroom realised by using such a system.