## 3 Results
### Demographics of the Patients Participating in Dataset
\begin{tabular}{c} 59.3\% \\ (14.5–81.3\%) \\ \end{tabular}  & \begin{tabular}{c} 25\% \\ (11.6–56.4\%) \\ \end{tabular}  & \ \begin{tabular}{c} 55.4\% \\ (13.7–85.6\%) \\ \end{tabular}  &
\begin{tabular}{c} 21.3\% \\ (8.9–42.2\%) \\ \  
We also examined the duration difference for the true positive detected events and their corresponding reference episodes. By considering the mean difference for all pairs of episodes (reference and detected), the duration of the events was underestimated by 3.2 s for tracheal sound recordings and 5.3 s for ambient sound recordings (Figure 5). More precisely, for the contact microphone, the error in the duration of the events was in the range of \(-17.3\) s to 23.8 s for 95% of all annotated events. The corresponding range for the ambient microphone was slightly widened: \(-19.1\) s to 29.8 s. It was particularly interesting that for the ambient microphone recordings, the mean duration difference between the detected and the corresponding reference event represented 10.51% of the duration of the corresponding reference event. For the case of the tracheal microphone recordings, this percentage was 4.43%. We also examined the difference in the detected and reference duration in different event categories. In particular, we classified detected events with respect to their reference duration in two categories: short-length events (10-20 s) and long events (>20 s). The difference between the reference and the detected duration provided smaller errors in the case of short length duration (see Supplementary Materials). The categorization of the events with respect to the type of the episode (apneas and hypopneas) provided minor  
Figure 4: Distribution of the duration of the set of reference apnea/hypopnea events—annotated by the clinical team—and the set of detected apnea/hypopnea episodes. (**a**) Tracheal contact microphone; (**b**) Ambient microphone. Despite the presence of a few events with duration in the range 60–150 s, we opted for presenting only the range 10–60 s to clearly indicate the strong differences between the examined distributions. Figure 5: Bland-Altman diagrams for the reference and detected duration of all true positive apnea/hypopnea events: (**a**) for the case of tracheal sound recordings; (**b**) for the case of ambient sound recordings. differences in the duration error between these main classes (see Supplementary Materials), keeping in mind that the total number of detected apneas was much larger than the corresponding count of detected hypopneas (Table 2). The Mean Apnea Duration of Each Patient Is Estimated with a Mean Error of 1.7 s for Tracheal Microphone and 3.2 s for the Ambient Microphone  
The Mean Apnea Duration (MAD) is an index indicative of the severity of the consequences of SAS. It is an index extracted for each patient by taking into account all apnea and hypopnea events. In the dataset we used, the mean error in the estimated MAD index for the tracheal sound was 1.7 s below the corresponding value of the reference MAD index of the patients. Based on the Bland- Altman plots illustrated in Figure 6, 95% of the patients in this dataset did not exceed the error margin of \(-\)8.7 s to 12 s. For the ambient microphone, these error values were slightly higher with the mean error in MAD estimation being 3.2 s below the reference value and the error margin for the majority of the patients (95%) being (\(-\)9.3 s, 15.8 s).