## 3 Results
\begin{table}
\begin{tabular}{c c c c|c c c c} \hline \hline  & \multicolumn{4}{c|}{**Tippet Classification Accuracy (\%)**} & \multicolumn{4}{c}{**Accuracy Using ROC Analysis**} \\ \hline
**Audio** & \begin{tabular}{c} **Normal–** \\ **Voluntary** \\ **Cough** \\ \end{tabular} & \begin{tabular}{c} **A Asthma** \\ **/Bronchial** \\ **Reactivity Cough** \\ \end{tabular} & \begin{tabular}{c} **Overall** \\ **Mean** \\ \end{tabular} & \begin{tabular}{c} **Sensitivity** \\ **(\%)** \\ \end{tabular} & \
\begin{tabular}{c} **Specificity** \\ **(\%)** \\ \end{tabular} &
\begin{tabular}{c} **AROC** \\ **(95\% CI)** \\ \end{tabular} \\ \hline
**MFCCs** & 78.91 & 74.03 & 76.24 & 78.39 & 75.54 & 0.84 (0.82–0.87) \\
**CQCCs** & 78.12 & 86.48 & 82.71 & 81.25 & 84.98 & 0.92 (0.90–0.93) \\
**Fused Result** & 82.55 & 84.76 & 83.76 & 82.81 & 84.76 & 0.91 (0.89–0.93) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Classification accuracy based on Tippet plot and Receiver Operating Characteristics (ROC) analysis. Figure 3: _Cont._ \begin{table}
\begin{tabular}{l c c c} \hline \hline  & \multicolumn{4}{c}{**Normal–Voluntary Cohort, N = 89**} \\ \hline  & \begin{tabular}{c} **Training Group** \\ **N = 71** \\ \end{tabular} & \
\begin{tabular}{c} **Testing Group** \\ **N = 42** \\ \end{tabular} &
\begin{tabular}{c} **\(p\)-Value** \\ **p-Value** \\ \end{tabular} \\ \hline
**Demographics Characteristics** & & & & \\ Age (months)—mean (SD) & 108.81(32.60) & 107.61(35.47) & 0.857 * \\ Sex (Male:Female) & 63:8 & 39:3 & 0.744 \\ Race (Malay:Chinese:Indian:Others) & 34:31:4:2 & 19:20:2:1 & 0.980 \\ Weight (kg)—mean (SD) & 32.76(13.89) & 34.97(16.62) & 0.680 * \\ \hline
**Past Medical History, N** & & & & 0.734 * \\ None & 52 & 32 & & \\ Asthma & 6 & 2 & & \\ Allergic rhinitis & 10 & 7 & & \\ Recurrent wheeze & 0 & 0 & & \\ Mild cold or recovered from URTI & 6 & 2 & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Clinical characteristics of the study population in the normal–voluntary cohort. Population numbers (N) in the Past Medical History might include children with more than one medical condition, presented non-contemporaneously. * Independent \(T\)-test, * Mann-Whitney \(U\) test, URTI (Upper Respiratory Tract Infection). The LLR values resulting from a classification model trained using MFCCs showed a relatively larger range (11.5) for normal-voluntary cough (obtained from the blue line in Figure 3A showing the range of values from -7.5 to 4). For classification models built using CQCCs features and those of a fused model, using both MFCCs and CQCCs, the corresponding range was relatively lower and was found to be 7.8 (-3.8 to 4) and 6.5 (-3 to 3.5), respectively. The zero-crossing point in the Tippett plots resulting from MFCCs and CQCCs were off-centered (with respect to LLR = 0 line), whereas for the fused model, the Tippett plot was rather more symmetric. Further, the cross-over point between the blue and red curves in the fused result was lower, i.e., the number of misclassifications in the fused result was therefore also lower. The accuracy analysis using ROC curves are shown in Figure 4. The best performance was obtained when fusing MFCCs and CQCCs. In this case, the accuracy, sensitivity, specificity, and AROC for differentiating normal-voluntary coughs from asthmatic coughs achieved 83.76%, 82.81%, 84.76%, and 0.91%, respectively. Figure 3: Tippett plots showing the performance of the classification model trained using features from (**A**) Mel-Frequency Cepstral Coefficients (MFCCs), (**B**) Constant Q Cepstral Coefficients (CQCCs), and (**C**) fused features.