# A Progressively Expanded Database for Automated Lung Sound Analysis: An Update
## 3 Results
### Performance Benchmark  
Performance measurement of the CNN-BiGRU models in segment and event detection on V1_Test and V2_Test is presented in Table 4. We can see that the models trained using V2_Train performed significantly better than those trained using V1_Train in terms of most measures in the segment- and event-detection of inhalation and CAS on V1_Test or V2_Test. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Database** & **HF\_Lung\_V1** & **HF\_Lung\_V2** \\ \hline \hline \multicolumn{2}{c}{Subjects} & 261 & 300 \\ \hline \multicolumn{2}{c}{No. of 15-s recordings} & 9765 & 13,957 \\ \hline \multicolumn{2}{c}{Total duration (min)} & 2441.25 & 3489.25 \\ \hline \multirow{2}{*}{Inhalation} & No. & 34,095 & 49,373 \\  & Duration (min) & 528.14 & 785.48 \\  & Mean (s) & 0.93 & 0.95 \\ \hline \multirow{2}{*}{Exhalation} & No. & 18,349 & 24,552 \\  & Duration (min) & 292.85 & 374.24 \\  & Mean (s) & 0.96 & 0.91 \\ \hline \multirow{2}{*}{CAS} & No. C/W/S/R & 13,883/8457/686/4740 & 21,558/13,139/914/7505 \\  & Duration (min) C/W/S/R & 191.16/119.73/9.46/61.98 & 292.85/186.97/12.82/93.06 \\  & Mean (s) C/W/S/R & 0.83/0.85/0.83/0.78 & 0.82/0.85/0.84/0.74 \\ \hline \multirow{2}{*}{DAS} & No. & 15,606 & 19,617 \\  & Duration (min) & 230.87 & 281.55 \\ \cline{1-1}  & Mean (s) & 0.89 & 0.86 \\ \hline \hline \end{tabular}  
* CAS/C: continuous adventitious sound, DAS: discontinuous adventitious sound. W: wheeze, S: stridor, R: rhonchus.  
\end{table} 
Table 2: Statistical data of lung sound files in HF_Lung_V1 and HF_Lung_V2 databases. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Database** & **HF\_Lung\_V1** & **HF\_Lung\_V2** \\ \hline \hline \multicolumn{2}{c}{**Data Set**} & **Training** & **Test** & **Training** & **Test** \\ \hline \multirow{2}{*}{I} & No. of 15-s recordings & 7809 & 1956 & 10,554 & 3403 \\ \cline{2-5}  & Total duration (min) & 1952.25 & 489 & 2638.5 & 850.75 \\ \hline \multirow{2}{*}{I} & No. & 27,223 & 6872 & 39,057 & 10,316 \\ \cline{2-5}  & Duration (min) & 422.17 & 105.97 & 623.02 & 162.46 \\ \cline{2-5}  & Mean (s) & 0.93 & 0.93 & 0.96 & 0.94 \\ \hline \multirow{2}{*}{E} & No. & 15,601 & 2748 & 18,334 & 6218 \\ \cline{2-5}  & Duration (min) & 248.05 & 44.81 & 292.88 & 81.37 \\ \cline{2-5}  & Mean (s) & 0.95 & 0.98 & 0.96 & 0.79 \\ \hline \multirow{2}{*}{C} & No. C/W/S/R & 11,464/7027/657/3780 & 2419/1430/29/960 & 17,361/11,453/866/5042 & 4197/1686/48/2463 \\ \cline{2-5}  & Duration (min) & 160.16/100.71/9.10/50.35 31.01/19.02/0.36/11.63 & 240.40/163.77/12.34/64.29 & 52.45/23.19/0.48/28.77 \\ \cline{2-5}  & Mean (s) & 0.84/0.86/0.83/0.80 & 0.77/0.80/0.74/0.73 & 0.83/0.86/0.85/0.77 & 0.75/0.83/0.60/0.70 \\ \hline \multirow{2}{*}{D} & No. & 13,794 & 1812 & 14,239 & 5378 \\ \cline{2-5}  & Duration (min) & 203.59 & 27.29 & 210.96 & 70.59 \\ \cline{1-1} \cline{2-5}  & Mean (s) & 0.89 & 0.90 & 0.89 & 0.79 \\ \hline \hline \end{tabular}  
* I: inhalation labels, E: exhalation labels, C: continuous adventitious sound labels, D: discontinuous adventitious sound labels, W: wheeze labels, S: stridor labels, and R: rhonchus labels.  
\end{table} 
Table 3: Statistics of lung sound files and labels in the HF_Lung_V1 and HF_Lung_V2 databases grouped by data sets. The improvement was also significant in the segment- and event-detection of exhalation on V1_Test. However, the models trained using V2_Train only showed slightly improved performance in event detection of DAS on V1_Test. Superior performance of the models trained using V2_Train in inhalation, exhalation, and CAS detection were shown in the ROC curves derived from V1_Test (Figure 6a-c) and V2_Test (Figure 6e-g). However, the ROC curves of the models greatly overlapped with each other in DAS detection (Figure 6d,h).