## 3 Subjective Evaluation Using Recording Sources and Headphone Listening
### Results  
The results of the subjective tests are shown in Figure 7. Error bars represent 5% significant yardsticks. All results of all items with headphones follow a similar tendency to that of the full-scale room model in Figure 5. Table 4 shows the results of the ANOVA on the main effects of the absorption coefficient on the eight evaluation items. \"Sense of room volume\", \(F\) (4, 20) = 2.20, \(p\) = 0.11 and \"feeling of oppression\", \(F\) (4, 20) = 0.28, \(p\) = 0.89 in the full-scale room model test and \"sense of quality\", \(F\) (4, 20) = 1.66, \(p\) = 0.20 in the headphone listening were not significant. \"Difference in feeling of silence\", \"reverbare\", \"feeling of silence\", and \"feeling of serenity\" were significant with respect to the absorption coefficient as well as in the result of the former test with the full-scale room model. The experimenter conducted interviews with all the participants after the experiment. The \"sense of quality\" was not significant in all sound fields because a participant group (three participants) replied a \"feeling of silence and appropriate reverberance\" for the space \"E\", whereas the other group replied \"feeling a high ceiling as in an entrance of a high graded hotel\" for the space \"A\". These responses were also obtained for \"user preference\", which explains the yardstick of \"user preference\" being as large as that of \"sense of quality\".  
The correlation coefficients between the psychological scores and the absorption coefficients of the five patterns were calculated. The calculation results are presented in Table 5. These five items are strongly correlated with the absorption coefficient. Thus, the primitive sensations, such as \"reverbare\", \"feeling of silence\", and \"feeling of serenity\", were stably evaluated using the headphone test with recorded resources by the dummy head as well as using the full-scale room model. In contrast, the \"sense of quality\" and \"user preference\" depended on the preference of the participant.  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Item**} & \multicolumn{2}{c}{**Main Effects F (4, 20)**} \\ \cline{2-3}  & **Full-Scale Model** & **Headphone Listening** \\ \hline Difference in feeling of silence & 12.76 ** & 42.36 ** \\ Reverberance & 65.00 ** & 24.07 ** \\ Feeling of silence & 10.17 ** & 45.79 ** \\ Feeling of serenity & 14.10 ** & 10.22 ** \\ Sense of room volume & 2.20 & 12.79 ** \\ Feeling of oppression & 0.28 & 4.38 * \\ Sense of quality & 9.00 ** & 1.66 \\ User preference & 9.38 ** & 4.48 ** \\ \hline \hline \end{tabular} \(F_{0.99}\) (4, 20) = 4.431, \(F_{0.95}\) (4, 20) = 2.866  
\end{table}
Table 4: Results of significant-difference tests of the main effects of the average absorption coefficient on the evaluation items.  
Figure 7: Results of the psychological experiment using recording sources and headphone listening. The eight figures show the psychological values of the five absorption patterns (A–E) for each subjective item. The error bars represent the 5% significant yardsticks.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Item** & **Correlation Coefficient** \\ \hline Difference in feeling of silence & 0.90 ** \\ Reverberance & 0.98 ** \\ Feeling of silence & 0.93 ** \\ Feeling of serenity & 0.97 ** \\ Sense of room volume & 0.55 \\ Feeling of oppression & 0.36 \\ Sense of quality & 0.76 ** \\ User preference & 0.96 ** \\ \hline \hline \end{tabular}
\end{table}
Table 5: Correlation coefficients between the psychological values of the full-scale modeling experiment and those of the headphone listening experiment for each evaluation item.